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RGClark
2008-Nov-26, 12:14 PM
...And with it, routine space access, the hydrogen economy, room-temperature superconductivity, and ultra large telescopes.

Very interesting article here reporting on researchers who had previously announced a rapid means of producing synthetic gem sized diamonds, now believe their methods will work to produce diamonds of arbitrary size:

Artificial diamonds - now available in extra large.
18:11 13 November 2008 by Catherine Brahic.
"A team in the US has brought the world one step closer to cheap, mass-produced, perfect diamonds. The improvement also means there is no theoretical limit on the size of diamonds that can be grown in the lab.
"A team led by Russell Hemley, of the Carnegie Institute of Washington, makes diamonds by chemical vapour deposition (CVD), where carbon atoms in a gas are deposited on a surface to produce diamond crystals.
"The CVD process produces rapid diamond growth, but impurities from the gas are absorbed and the diamonds take on a brownish tint.
"These defects can be purged by a costly high-pressure, high-temperature treatment called annealing. However, only relatively small diamonds can be produced this way: the largest so far being a 34-carat yellow diamond about 1 centimetre wide.
"Microwaved gems
"Now Hemley and his team have got around the size limit by using microwaves to "cook" their diamonds in a hydrogen plasma at 2200 C but at low pressure. Diamond size is now limited only by the size of the microwave chamber used.
"The most exciting aspect of this new annealing process is the unlimited size of the crystals that can be treated. The breakthrough will allow us to push to kilocarat diamonds of high optical quality," says Hemley's Carnegie Institute colleague Ho-kwang Mao."
http://www.newscientist.com/article/dn16036

Original research article:

Enhanced optical properties of chemical vapor deposited single crystal diamond by low-pressure/high-temperature annealing.
Yu-fei Meng, Chih-shiue Yan, Joseph Lai, Szczesny Krasnicki, Haiyun Shu, Thomas Yu, Qi Liang, Ho-kwang Mao, and Russell J. Hemley
Published online before print November 12, 2008, doi: 10.1073/pnas.0808230105
PNAS November 18, 2008 vol. 105 no. 46 17620-17625
http://www.pnas.org/content/105/46/17620 [abstract]

I had discussed the earlier research that showed they could make synthetic diamonds of perhaps 50% greater hardness than natural diamond. From this I suggested this should mean the strength should also be increased by this amount and could result in ultra large telescope mirrors, perhaps to 30 meters across, if the process could be scaled to arbitrary sizes, as now appears likely:

Newsgroups: sci.astro, sci.physics, sci.optics, sci.materials
From: "Robert Clark" <rgregorycl...@yahoo.com>
Date: 11 Dec 2004 12:48:10 -0800
Local: Sat, Dec 11 2004 3:48 pm
Subject: Re: Can diamond now be used for telescope mirrors?
http://groups.google.com/group/sci.astro/msg/8d2744a0b5fa94b4?hl=en

Here I suggested that use of ultra high strength microspheres or microfibers would be able to solve the problem of finding lightweight storage tanks for the hydrogen fuel on the VentureStar reusable launch vehicle:

Newsgroups: sci.astro, sci.space.policy, sci.physics, sci.energy
From: Robert Clark <rgregorycl...@yahoo.com>
Date: Fri, 5 Sep 2008 20:32:39 -0700 (PDT)
Local: Fri, Sep 5 2008 10:32 pm
Subject: High strength microspheres for hydrogen storage (was: High strength fibers for hydrogen storage on the VentureStar.)
http://groups.google.com/group/sci.astro/msg/4bddfa864aa04056?hl=en

If the high strength material at the microscale were diamond, the weight of the propellant tanks could be reduced by a factor of 100, which would make feasible not only the VentureStar but also the other competing NASA reusable launch vehicle proposals. With the newly announced process now being able to make diamond in bulk sizes, the tanks would not need to consist of numerous microspheres or microfibers but a single macrosized tank. Note that such lightweight, high strength tanks would also solve the storage problem for hydrogen for the hydrogen economy.
Not only could the diamond be used for the propellant tanks but also for the strength bearing structures of the entire craft since diamond also has ultra high compressive strength as well as tensile strength. The weight of the vehicles could conceivable be reduced by a factor of 100: instead of 200,000 lbs., only 2000 lbs.

Metallic hydrogen has been considered an ideal rocket fuel if it could be produced because it is of high density yet it's energy content would give it a fuel efficiency of 4 times that of the best chemical propellants now used. Theoretical modeling also suggests it could be stable at room temperature once produced and would be a superconductor.
Experimental and theoretical work suggested metallic hydrogen would be produced at pressures of 4.5 megabars, 450 GPa:

Apr 10, 2002
Hydrogen metal on the horizon.
"Scientists have long expected solid hydrogen to become a metal when it is compressed, but so far electrical conductivity has only been detected in liquid hydrogen. Now an experimental study of solid hydrogen at pressures up to 320 GPa predicts that it will become metallic at a pressure of 450 GPa over four million times atmospheric pressure. Ren LeToullec and co-workers at the CEA in France also found that solid hydrogen becomes opaque or black under compression (P Loubeyre et al 2002 Nature 416 613)."
http://physicsworld.com/cws/article/news/5307

Attempts to create ultra high pressures in the megabar range frequently involve using diamond anvils at the microscale. However, natural diamond has maximum compressive strength of about 400 GPa. If it is indeed the case that the 50% increase in hardness of the new synthetic diamonds over natural diamond also indicates a corresponding increase in compressive strength, this would put diamond anvils using these synthetic diamonds within the compressive strength range required to produce metallic hydrogen.


Bob Clark

GOURDHEAD
2008-Nov-26, 01:54 PM
Metallic hydrogen has been considered an ideal rocket fuel if it could be produced because it is of high density yet it's energy content would give it a fuel efficiency of 4 times that of the best chemical propellants now used. Theoretical modeling also suggests it could be stable at room temperature once produced and would be a superconductor.
Experimental and theoretical work suggested metallic hydrogen would be produced at pressures of 4.5 megabars, 450 GPa: In what other ways does it mimic dark matter? Pressures much higher than 4.5 megabars must have existed in the time interval between BB + 10^-43 and 10^-1 seconds. I've never heard of a supercooled solid but room temperature solid hydrogen suggests such a state. Would it sublimate in a contollable manner?

samkent
2008-Nov-26, 02:29 PM
This reminds me of the promises of the flying car in every driveway and electricity so cheap it wouldn't be metered.

stutefish
2008-Nov-26, 05:19 PM
This reminds me of the promises of the flying car in every driveway and electricity so cheap it wouldn't be metered.
Huh.

Those are vague, general ideas that would require several breakthroughs in several different fields, none of which are clearly defined.

These are clear, specific breakthroughs in specific fields, for which a variety of applications are already clearly implied.

NEOWatcher
2008-Nov-26, 05:38 PM
...These are clear, specific breakthroughs in specific fields, for which a variety of applications are already clearly implied.
Not if you look at nuclear energy. I remember it was supposed to be so cheap that it wouldn't be metered.
So yes; I agree with Samket's comment. It does sound like a great step, or maybe even a breakthrough, but I doubt that the technology will really take car of that wishlist any time soon. For instance. To go from a current 1cm diamond, to a 30 meter telescope lense might be technically feasible, but the investment path may take a very long time.

novaderrik
2008-Nov-26, 10:14 PM
this is all well and good, but how long before Big Diamond makes the inventor an offer he can't refuse and then makes this all disappear?
that's how these things work, right?

PraedSt
2008-Nov-26, 10:19 PM
this is all well and good, but how long before Big Diamond makes the inventor an offer he can't refuse and then makes this all disappear?
that's how these things work, right?
No.

novaderrik
2008-Nov-27, 02:29 AM
No.

but i read it on the internets...
the cheap and easy to produce diamond of any size imaginable will go the way of the 100mpg carburetor of the 50's and the TRUTH about UFO's today..

Vallkynn
2008-Nov-28, 10:17 AM
Not if you look at nuclear energy. I remember it was supposed to be so cheap that it wouldn't be metered.
So yes; I agree with Samket's comment. It does sound like a great step, or maybe even a breakthrough, but I doubt that the technology will really take car of that wishlist any time soon. For instance. To go from a current 1cm diamond, to a 30 meter telescope lense might be technically feasible, but the investment path may take a very long time.

Well, this is nano-materials technology, being carbon based or something else. It's generally accepted that if we could align the atoms of any alloy we would achieve a much bigger resistance and several other improved properties. So this doesn't surprise me, it's a natural evolution on nano-materials.

The problem with the flying car is energy. If energy was cheaper then for sure flying cars would be around.

Ara Pacis
2008-Nov-29, 11:10 AM
The problem with the flying car is energy. If energy was cheaper then for sure flying cars would be around.

Or denser.

mugaliens
2008-Nov-29, 01:44 PM
Not if you look at nuclear energy. I remember it was supposed to be so cheap that it wouldn't be metered.

And it would have been, except for all the design modifications required for active safety controls, which result in a cost between 3.1 and 8.2 cents/kWh. Naturally, the waters are heavily muddied by the various subsidizing that occurs throughout many of the stages of nuclear power production and waste management.

Ara Pacis
2008-Nov-29, 11:17 PM
I'm actually a little confused by statements in this thread. I know diamonds are hard, but from what I've read, they're not particularly strong. They can't be scratched but they can be shattered. Two other problems are combustion, making it useless for engine nozzles and similar applications and its solubility in iron.

NEOWatcher
2008-Dec-02, 06:33 PM
I'm actually a little confused by statements in this thread. I know diamonds are hard, but from what I've read, they're not particularly strong. They can't be scratched but they can be shattered. Two other problems are combustion, making it useless for engine nozzles and similar applications and its solubility in iron.
From what little I gathered (mostly from the first link where I stopped at the phrase "you will need to login or make a payment"), they did mention a harder multiple-crystalline structure than a normal diamond's single-crystalline structure.
I would assume that goes for hardness as well as strength. I don't know about combustion. And it appears the structure would also help clarity.

RGClark
2008-Dec-05, 08:52 PM
Forbidden Planet - Wikiquote.
Dialogue.
"Altaira: Robby, I must have a new dress, right away.
Robby: Again?
Altaira: Oh, but this one must be different! Absolutely nothing must show - below, above or through.
Robby: Radiation-proof?
Altaira: No, just eye-proof will do.
Robby: Thick and heavy?
Altaira: Oh, no, no, it’s got to be the softest, loveliest thing you’ve ever made for me, and fit in all the right places, with lots and lots of star sapphires.
Robby: Star sapphires take a week to crystallise properly, would diamonds or emeralds do?
Altaira: Well, if they’re large enough."
http://en.wikiquote.org/wiki/Forbidden_Planet


Indeed!


Bob Clark

RGClark
2008-Dec-06, 03:10 PM
The aluminum alloy liquid hydrogen tank used for the space shuttle is on the order of 10 meters wide, with a skin thickness in the range of 5 to 10 millimeters. To use a similar sized tank for liquid hydrogen using diamond while reducing the weight by a factor of 100, you would need to reduce the thickness to only about 100 microns. That is quite thin for a macro sized tank, about the thickness of a sheet of paper.
The research team producing the synthetic diamonds have already created diamonds of size a cm across. The analogous thickness for a LH tank 1 cm across would be one with a thickness of only 100 nanometers. It would be interesting to find out if the researchers hollowed out one of their cm-sized diamonds to make a LH container out of it of only 100 nanometer thickness, would it have comparable strength to the LH tanks now used.



Bob Clark

mugaliens
2008-Dec-07, 12:34 AM
This reminds me of the promises of the flying car in every driveway and electricity so cheap it wouldn't be metered.

What? I have that. What? (oops - scoots back to alternative universe)

Diamonds may be the hardest natural material known to man, but that doesn't make it the God-material. They're pretty dense (aka "heavy" at 3.52 specific gravity), they're not suitable for machining ferrous alloys as they're soluable in the iron at high temperatures! While they're extremely hard, they're not very tough (resistance to breakage from forceful impact). Their toughness is considered "fair to good." You can easily break one with a hammer. In fact, they're poor compared to most engineering materials. And their cleavage plane makes them quite susceptible to breakage when forces are aligned in certain ways. They're not even the most stable form of carbon - graphite has that distinction, and diamonds will eventually revert to graphite under high heat conditions, and if heated in the presence of oxygen, they burn at 1500 deg F, which is cooler than the melting point of many metals, including that of gold - 1947.52 deg F.

On the other hand, they're optically isotropic with a tensile strength between 60 GPa (observed) and theoretically, between 90 and 225 GPa. By comparison, Kevlar's tensile strength is around 3.5 GPa, and stainless steel is between 0.65 and 1 GPa. A multi-walled carbon nanotube was tested to have a tensile strength of 63 GPa. So diamonds are definately way, way up there in this respect.

One unusual characteristic is that while they're excellent insulators, they're exceptionally good conductors of heat, more than 5 times better than copper, making them highly useful in the semiconductor industry to prevent silicon and other materials from overheating.

Lord Jubjub
2008-Dec-07, 03:17 AM
Speaking of Big Diamond, deBeers is already taking steps to distinguish man-made diamond from natural diamond by putting a code number on all of their diamonds and saying that the presence of a code number shows superiority to manmade diamonds.

Reminds of Dr. Suess's Sneetches story. . .

Swift
2008-Dec-08, 04:25 AM
Speaking of Big Diamond, deBeers is already taking steps to distinguish man-made diamond from natural diamond by putting a code number on all of their diamonds and saying that the presence of a code number shows superiority to manmade diamonds.

Actually, I'm rather surprised that is necessary. I have no personal experience with diamonds, but I have grown such synthetic gemstones as amethyst and citrine.

Most man-made gemstones have enough distinguishing characteristics that they are relatively easy to tell apart from the natural ones. These characteristics include trace impurities and microscopic defects, such as bubbles or inclusions.

And for the jewelry market, even if the synthetic stones are more "perfect", I suspect that the "natural" ones will always command a higher price (they do for the currently available ones).

PraedSt
2008-Dec-08, 01:02 PM
Speaking of Big Diamond, deBeers is already taking steps to distinguish man-made diamond from natural diamond by putting a code number on all of their diamonds and saying that the presence of a code number shows superiority to manmade diamonds.
I heard that too Lord Jubjub. It's just simple branding. I interpreted it to mean that De Beers was concerned about future competition- which isn't a bad thing.

Technically branding is done to reduce the ability of your product to be substituted by a similar product. As Swift said, this can allow you to charge, and receive, a higher price. A good analogy to this, and the OP, would be a natural mineral water brand such as Perrier. The non-flavoured varieties of course.

RGClark
2008-Dec-31, 02:07 AM
Here's the research teams home page:

Carnegie/DOE Alliance Center - CDAC.
http://cdac.gl.ciw.edu/

They have there a link to the full text of the article:

Enhanced optical properties of chemical vapor deposited single crystal diamond by low-pressure/high-temperature annealing.
Yu-fei Meng, Chih-shiue Yan, Joseph Lai, Szczesny Krasnicki, Haiyun Shu, Thomas Yu, Qi Liang, Ho-kwang Mao, and Russell J. Hemley.
PNAS November 18, 2008 vol. 105 no. 46 17620-17625.
http://cdac.gl.ciw.edu/images/stories/MengYufeiPNAS2008.pdf

The article details how their new low pressure annealing process is able to remove optical, color, and physical defects in diamond. Their theory for how this works explains why the annealing, which makes the diamond stronger, also happens to remove discolorations in the diamond. Some very nice color illustrations of synthetic, clear centimeter size diamonds in the article.
They also explain that both the creation of the diamond and the annealing process can now be done at low pressures:

"Methods
SC-CVD diamond samples were produced by the MPCVD method described
elsewhere (2, 3). Typically the diamond samples were grown under the following
conditions: N2/CH4  0.25.0%, CH4/H2  1220%, total pressures of
120220 torr, and temperatures of 900-1500 C. For the purpose of annealing,
a 6 kW, 2.45 GHz microwave plasma CVD system with a redesigned cavity and
molybdenum substrate stage was used to generate stable and energetic
hydrogen plasmas (2). SC-CVD diamond plates were heated in the CVD chamber
to temperatures in the range 1400 C to 2200 C, at pressures between 150
and 300 torr. Typically, samples were heated stepwise to the maximum
annealing temperature, kept at the maximum temperature for a chosen time,
and ramped down to room temperature."
p. 17,624

This is at less than 1/2 atmosphere. Previously, producing or annealing the diamond required pressures in the thousands of atmospheres range. This means it can be done much more cheaply. As another researcher put it:

Artificial diamonds - now available in extra large.
18:11 13 November 2008 by Catherine Brahic.
"Threat to commerce
"The team's method 'could be routinely run in any laboratory where it is needed,' says Alexandre Zaitsev, a physicist at the City University of New York, whose work also includes diamonds. 'When considered in combination with the high-growth-rate technique of CVD diamonds, it seems to be a starting point of mass-scale production of perfect diamond material at a low price.'"
"Zaitsev considers low-pressure annealing at temperatures greater than 2000 C to be a "breakthrough in diamond research and technology".
"The improving quality of synthetic diamonds threatens the natural diamond market. While 20 tonnes of natural diamonds are mined annually, some 600 tonnes of synthetic diamonds are produced each year for industrial use alone."
http://www.newscientist.com/article/dn16036


Bob Clark

RGClark
2009-Jan-02, 11:00 PM
I believe that the recent development of low cost methods of diamond production will have wide ranging impact on aerospace and other areas of technology.
Diamond has the highest compressive strength of any known material in addition to the highest melting point for a single element, in the range of 4000 C.

The space shuttle main engines and the RS-68 engines proposed to be used on the Ares shuttle successor have to be heavy because they have to have thick combustion chambers and large nozzles made of copper or steel, because of the need to dissipate the heat rapidly. Diamond however is 5 times better than copper in thermal conductivity, at about 1/3 the weight, so would be better than copper by a factor of 15 times for the weight required:

List of thermal conductivity values.
http://en.wikipedia.org/wiki/Thermal_conductivity#List_of_thermal_conductivity_ values

Note also that the temperature reached in the space shuttle engines of 3,300 C is less than the melting point of diamond. Furthermore, to increase the safety factor, it is known the melting point for diamond increases under pressure. So the diamond could be used in "prestessed" form to increase its melting point even further. Note then this would eliminate the need for the complicated and expensive liquid cooling channels throughout the walls of the combustion chamber and nozzle.
So you could reduce the weight of the SSME's from 7,000 lbs. to 1/15th of this to around 500 lbs, while maintaining its reusability.
The weight of RS-68 engine could also be similarly reduced and be made reusable by no longer needing the ablative surfaces on the nozzle to dissipate the heat.
A problem that would need to be solved though is the coating to put on the diamond to protect it from the combustion. While diamond does have a quite high melting point, it will burn in oxygen at around 600 C. So a high temperature coating would have to be put on the diamond used in the combustion chamber and in the nozzle.
This is a similar to how carbon-carbon composites have been used for the highest temperature areas on the shuttle orbiter body. Made of carbon, these composites will also burn in oxygen at temperatures lower than the ones they have to withstand during shuttle reentry. Then they are coated to protect them from oxygen.
For the temperatures reached in the combustion chambers and nozzles of the engines which are about twice those reached on the surfaces of the orbiter body during reentry, you would need higher temperature coatings to withstand this. Some possibilities might be for example hafnium carbide and tantalum hafnium carbide:

Hafnium(IV) carbide.
http://en.wikipedia.org/wiki/Hafnium_carbide

Tantalum hafnium carbide.
http://en.wikipedia.org/wiki/Tantalum_hafnium_carbide

Ceramic materials are being investigated for rocket engine components:

Ceramic Materials for Reusable Liquid Fueled Rocket Engine Combustion Devices.
http://ammtiac.alionscience.com/pdf/AMPQ8_1ART06.pdf

This article states that likely some form of active cooling would be needed for the hottest areas in the combustion chamber and the nozzle, however, it does not consider the possibility of the high temperature resistance and heat dissipation capability of diamond.


Bob Clark

cjameshuff
2009-Jan-03, 01:42 AM
Diamond has the highest compressive strength of any known material

However, it is brittle, with a particular tendency to fracture along certain planes.



in addition to the highest melting point for a single element, in the range of 4000 C.

And burns in air at a few hundred degrees C.

The advancements in producing diamond films and bulk diamond are certainly going to be extremely useful, but diamond is not the supermaterial you seem to think it is. It might be useful in the heat transfer portions of nuclear thermal engines due to its thermal conductivity, but we're not going to be building rocket engines or fuel tanks out of it. Diamondoid tapes and fibers might be useful in composites, but I expect nanotubes and graphene to dominate that field.

Ara Pacis
2009-Jan-03, 12:25 PM
There are two reasons for the tubing on the nozzles: cooling the nozzles and, more importantly, warming the propellants. If you aren't going to warm up the cryogenic propellants/fuels with engine waste heat, then how will you do it? Also, if diamond is a good conductor of heat, then you will need someplace for that heat to be conducted too, such as a radiator or to the aforementioned cryo-fuels. It's when something is a bad conductor of heat that you don't have to worry about cooling it, such as happens with the thermal tiles.

mugaliens
2009-Jan-03, 04:18 PM
Speaking of Big Diamond, deBeers is already taking steps to distinguish man-made diamond from natural diamond by putting a code number on all of their diamonds and saying that the presence of a code number shows superiority to manmade diamonds.

Reminds of Dr. Suess's Sneetches story. . .

LOL! That's so true. In fact, the value of diamonds is vastly overrated, largely created as a result of monopolism and advertising on the part of deBeers.

The more people realize this, the less power deBeers will have over how you spend your hard-earned money.


The advancements in producing diamond films and bulk diamond are certainly going to be extremely useful...

I am very thankful that deBeers does not control the synthetic diamond market.


...but diamond is not the supermaterial you seem to think it is.

The believe that diamond is a supermaterial is merely fallout from deBeers' many commercials intent on increasing the admiration and appreciation of diamonds, thereby increasing their value.

They may very well be a very pretty rock, and have some neat industrial uses, but in the end, it's still just a rock. If we can produce that rock, en masse, particularly in the jewelry arena, and cheaply enough (say, half price) to compete with natural diamonds, that will entirely satisfy most people with respect to what adorns their fingers and other jewelry uses.

mugaliens
2009-Jan-06, 06:34 PM
I think it's the whole strength/weight ratio issue, as well as an inherent resistance to natural phenomena which could damage or destroy it's integrity.

We've mentioned this several times.

Swift
2009-Jan-06, 08:40 PM
They may very well be a very pretty rock, and have some neat industrial uses, but in the end, it's still just a rock. If we can produce that rock, en masse, particularly in the jewelry arena, and cheaply enough (say, half price) to compete with natural diamonds, that will entirely satisfy most people with respect to what adorns their fingers and other jewelry uses.
I've said this before, but as far as jewelry is concerned, that might not be true. I spent part of my career making synthetic amethyst. Even though by any measurable or observable (naked eye) characteristic our material was better than natural, consumers were willing to pay more to jewelry makers for "natural" and thus we actually got paid less than the going rate for natural stones. The only time we really had a good business was when a big portion of the supply of natural stones was cut off by unrest in Africa.

Of course, none of this applies to industrial or space uses of such materials.

RGClark
2009-Jan-10, 01:40 AM
Mugs, you asked on another thread how this new report in the Proceedings of the National Academy of Sciences shows you can make harder diamonds.
I read again the research teams web site:

Chemical Vapor Deposition (CVD) Lab.
...
"Low-Pressure/High-Temperature Annealing Single crystal diamond produced by chemical vapor deposition (CVD) at very high growth rates (up to 150 μ/h) has been successfully annealed without graphitization at temperatures up to 2200C and pressures below 300 torr. The low pressure/high temperature (LPHT) annealing enhances the optical properties of this high-growth rate CVD single crystal diamond. Significant decreases are observed in ultraviolet to visible and infrared absorption as well as photoluminescence spectra. The dramatic decrease in optical absorption after LPHT annealing arises from the changes is defect structure associated with hydrogen incorporation during CVD growth. There is a decrease in sharp line spectral features indicating a reduction in nitrogen-vacancy-hydrogen (NVH-) defects. The measurements indicate an increase in relative concentration of nitrogen-vacancy (NV) centers in nitrogen-containing LPHT-annealed diamond as compared to as-grown CVD material. The large overall changes in optical properties as well as the specific types of alterations in defect structure induced by this facile LPHT processing of high-growth rate single-crystal CVD diamond will be useful in the creation of diamond for a variety of scientific and technological applications [11].
"Ultratough Single-Crystal Diamond The high quality, gem-size single crystal diamonds at very high growth rate have tunable mechanical properties. Vickers hardness tests were used to evaluate the hardness and fracture toughness of these crystals. It was found that the nominal fracture toughness of CVD diamonds grown under H2/CH4/N2 chemistry is around 15 ~ 20 MPa m1/2, with respect to 10 2 MPa m1/2 of Type Ib diamonds, and 8 4 MPa m1/2 of natural Ia and IIa diamonds. Further enhancement in toughness was observed for single crystal diamonds grown under newly developed chemistry; the fracture toughness could be improved by at least a factor of two. No radical fracture was observed around Vickers indentation craters, creating difficulty in measuring this very high toughness. These new diamonds could be used in new application in optics, electronics, and mechanical applications. In particular, low cost tough and ultratough CVD single crystal diamonds can play an important role in machining and abrasive industries. [12]"
http://cdac.gl.ciw.edu/index.php?option=com_content&task=view&id=99&Itemid=40

Notice that they discuss separately the low pressure work, which is what the Proceedings paper is about, and the ultratough diamonds work. This leads me to think the ultratough diamonds still require the higher pressures, in the range of 50,000 to 70,000 atmospheres.

This is supported by what it says in their patent application:

(WO/2007/018555) ULTRATOUGH CVD SINGLE CRYSTAL DIAMOND AND THREE DIMENSIONAL GROWTH THEREOF.
"In another embodiment, the aforementioned method further comprises annealing the single-crystal diamond at pressures in excess of about 5 to about 7 GPa and temperatures of from about 2000 C to about 2700 C such that the hardness is from about 100 to about 160 GPa. In yet another embodiment, the single crystal diamond prior to annealing is substantially colorless."
...
"Various colorless to brown single crystal CVD diamonds were HPHT annealed (aCVD); all were all made colorless at temperatures of about 2000-2700 C and about 5-7 GPa for about 10 minutes using a belt-type apparatus. Before HPHT annealing, these CVD diamonds exhibited high toughness, and after annealing the hardness of these diamonds increased dramatically."
http://www.wipo.int/pctdb/en/wo.jsp?IA=US2005032199&DISPLAY=DESC

HPHT means high pressure, high temperature.

Still, even the low pressure work likely would produce diamond at least as strong as natural diamond, which is still 100 times stronger than steel. And even natural diamond has fracture toughness in the range of 8 to 10, which as I said in another post is higher than that of carbon fiber which has found wide application in the aerospace industry.
Also, interesting in the patent application is that in one embodiment they are able to achieve fracture toughness of 40, which is even better than the high strength aluminum alloys used in aerospace.


Bob Clark

RGClark
2009-Jan-10, 12:00 PM
The post where I discussed the fracture toughness of diamond compared to other materials was in another thread, here it is:

================================================== ============
If you look at the description of the method to make this large size synthetic diamond it is well within the capabilities of most university physics labs.
Within a year you're going to see universities across the country and around the world making golf ball sized diamonds. Within 5 years you'll see diamond being used in contruction materials.
Diamond is *relatively* brittle, but even brittle structures like glass can have important uses for improving strength. For instance glass fibers, fiberglass, have been used in light weight car bodies, boat hulls, tennis rackets, etc. because it is lightweight yet still high in tensile strength.
And concrete of course is quite brittle yet is extremely important in construction. The quantity used in materials science to measure brittleness is "fracture toughness". The table on this page shows the brittleness of concrete is worse than some types of ceramics and in fact is comparable to some forms of glass:

Fracture toughness.
"Fracture toughness is a quantitative way of expressing a material's resistance to brittle fracture when a crack is present. If a material has a large value of fracture toughness it will probably undergo ductile fracture. Brittle fracture is very characteristic of materials with a low fracture toughness value."
http://en.wikipedia.org/wiki/Fracture_toughness

And carbon fiber of course has become extremely important as a strengthening material in aerospace. It is what has for instance made possible Scaled Composite's commercial suborbital launch system.
Well, carbon fiber is more brittle than diamond! This report shows the fracture toughness of carbon fiber is in the range of 1 to 2 (which is worse than that of ceramics):

DIRECT MEASUREMENT ON FRACTURE TOUGHNESS OF CARBON FIBER.
http://extra.ivf.se/eccm13_programme/abstracts/812.pdf

However, this web page by the team that developed the new large scale diamond synthesis method states natural diamond has fracture toughness in the range of 8 to 12 depending on type:

Chemical Vapor Deposition (CVD) Lab.
http://cdac.gl.ciw.edu/index.php?option=com_content&task=view&id=99&Itemid=40

But what is extremely important here is that not only does the new method increase the hardness of the synthetic diamond over that of natural diamond, but it increases the fracture toughness as well.
Indeed in their patent application they say their new method creates diamond of fracture toughness of 30:

(WO/2007/018555) ULTRATOUGH CVD SINGLE CRYSTAL DIAMOND AND THREE DIMENSIONAL GROWTH THEREOF.
http://www.wipo.int/pctdb/en/wo.jsp?IA=US2005032199&DISPLAY=DESC

Note that this is better than the fracture toughness of standard aluminum and close to that of aluminum alloys such as those used in the aerospace industry! See the table again on the "Fracture toughness" page.

There is little doubt that diamond will be used in both the construction and aerospace industries, and soon.

================================================== ============

RGClark
2009-Jan-17, 04:40 AM
The cheap availability of low cost, arbitrarily large size diamond
will have revolutionary effects on every aspect of industry:
construction, aerospace, automobiles, computers, ultra long life
energy storage methods, the hydrogen economy, high energy propulsion,
renewable energy, space construction, etc.

I have already discussed some of these.
For the other ones, for the automobile industry imagine a car that
you could fold up and take with you as carry on luggage.
Alternatively, instead of making them lighter by a factor of 100 you
might want to keep them the same weight but making them more resistant to impacts.
The damage a car will receive by an impact scales as the kinetic
energy, which varies as the square of the velocity.
Cars nowadays will sustain minimal damage at a speed of say 15 mph.
Since diamond is a 100 times stronger than steel for the same weight,
a car of the same weight made of diamond would be able to sustain
impacts of 150 mph with minimal damage, as well as minimal injuries to
the passengers.
Diamonds for several years now have been investigated for its
applications in computer chips. Diamond used for the semiconductor
instead of silicon dioxide would increase the speed of computer speeds
several times. Because of its high melting point it would also
eliminate the need for heat dissipation methods. An interesting
application of this fact is that a space probe lander to Venus where
the surface temperature can reach 800 degrees F would not need special
cooling methods to last indefinitely on the Venusian surface, which
has been a main stumbling block for planned lander missions to Venus.
One method used for energy storage is by flywheels. This is limited
by the strength of the materials used. The strongest materials used
now are carbon fibers. Diamond with a strength 10 times as great as
carbon fiber would allow 10 times greater energy storage. Other
methods would allow electrical charge storage for batteries using
ultra strong materials.
For renewable energy, wind turbines are limited by the power they can produce by the size of the rotors. The current limit is around 5 megawatts using rotors about 100 meters across. I'll give a heuristic argument that diamond can increase this maximum size to 1 km across, with an increase in the power to 500 megawatts, since the power scales as the cross-sectional area. (Critical responses to the argument are welcome.)
If you make the rotors 10 times larger length, the volume increases
by the cube of 10, or 1,000 times, and the weight will increase by
1000. The strongest material used now for the rotors is carbon fiber.
If we made the material instead of diamond, its density is twice as
great so the proposed 1 km wide diamond rotor would actually weigh
2,000 times more than a 100 meter carbon fiber one.
However, the supporting area of the rotor will increase by the
square of 10 or 100 times. Then the pressure will be increased by
2,000/100 = 20 times.
An increase of strength to density ratio of diamond over carbon fiber
of 10 to 1 means its strength is 20 times higher because its density
is twice is high. In other words the 1 km diameter rotor would be able
to support its own weight.
The diamond's high compressive strength would also allow a tower made
of diamond to reach the 1 km or higher height required for the rotor
while still supporting the extreme weight and torque forces of a 1 km
wide rotor.
One megawatt of power is enough to power about 1,000 homes. So 500
megawatts is enough for about 500,000 homes. With an average of about
2.5 people per household, this is enough for a city of about 1.25
million people. So a single one of these could power a city of over a
million people. No more than 10 would be enough for each of the
largest cities in the country.
The ISS space station can hold a crew complement of 6. Imagine one
made of diamond that could be 100 times larger at the same weight,
and at the same cost, using the same number of launches to lift the same weight. So it could hold a community of 600 people. For a station
this size you might even have a rotating station to allow artificial
gravity by centrifugal force.


Low cost, bulk sized diamonds.
This changes everything.


Bob Clark

cjl
2009-Jan-17, 07:28 AM
The main problem with your arguments:

Diamond is brittle. A 1km diameter wind turbine would probably fall apart the instant it was built because of this fact. Yes, diamond is a good material, but it's hardly the all-curing wonder material that you seem to think it is. In addition, your car example is incorrect - even if the car could survive a 150mph impact (which it couldn't - as I said before, diamond is brittle), the people inside would likely be killed when they impacted the inside of the car at 150mph.

RGClark
2009-Jan-17, 06:46 PM
The main problem with your arguments:

Diamond is brittle. A 1km diameter wind turbine would probably fall apart the instant it was built because of this fact. Yes, diamond is a good material, but it's hardly the all-curing wonder material that you seem to think it is. In addition, your car example is incorrect - even if the car could survive a 150mph impact (which it couldn't - as I said before, diamond is brittle), the people inside would likely be killed when they impacted the inside of the car at 150mph.

You have to quantify your terms. Simply saying a material is "brittle" is insufficient. As I said the new diamond manufacturing method can produce diamond that is less brittle than the high strength aluminum alloys long used in the aerospace industry, while being 100 times stronger, and it is less brittle than the carbon fiber composites increasingly being used in aircraft and spacecraft, while being 10 times stronger.


Bob Clark

mugaliens
2009-Jan-19, 03:09 PM
You have to quantify your terms. Simply saying a material is "brittle" is insufficient. As I said the new diamond manufacturing method can produce diamond that is less brittle than the high strength aluminum alloys long used in the aerospace industry, while being 100 times stronger, and it is less brittle than the carbon fiber composites increasingly being used in aircraft and spacecraft, while being 10 times stronger.

Bob Clark

You've made tons of claims, Bob. Saying "it's better than x" doesn't cut the mustard. In what way? What specific value for which material property are you using in your comparison?

You've provided very few facts, and if you are either unable or unwilling to follow through, I will request this thread be moved to ATM.

It's not that difficult! Simply fill in the blanks of your super-material using SI units. You may find the requisite fields at this List of Materials Properties (http://en.wikipedia.org/wiki/List_of_materials_properties). The ones in which we're particularly interested in are the first three: Mechanical, Electrical, and Thermal.

Don't worry if you're unable to provide answers to all of them, particularly the thermal properties. Just give us what you have. Corrosion resistance and Reactivity would be nice, too, as would it's permeability.

This will help us to evaluate your claims from a rational, scientific basis rather than a wordy plethora of claims that it's better than sliced bread.

Thanks.

djellison
2009-Jan-19, 07:13 PM
I will request this thread be moved to ATM.

Seconded - the use of artificial diamond as a building material or even aviation building material is ATM.

Jerry
2009-Jan-19, 11:46 PM
You have to quantify your terms. Simply saying a material is "brittle" is insufficient. As I said the new diamond manufacturing method can produce diamond that is less brittle than the high strength aluminum alloys long used in the aerospace industry, while being 100 times stronger, and it is less brittle than the carbon fiber composites increasingly being used in aircraft and spacecraft, while being 10 times stronger.

New material testing is one of the fundamental R&D costs - even minor changes require complete validation of the manufacturing process, compatibility testing, aging, tensile properties, thermal properties, crack propegation - and there are few if any shortcuts: How do you quantify a year of Florida weathering in less than a year?

Any fundamentally new system of materials will require years of evaluation before they can be included in any rational manned program. Both of the Shuttle failures can be traced to poor or incomplete characterization of new materials. (O-ring design/sealing and insulation bonding at cold temperatures.)

RGClark
2009-Jan-21, 06:33 PM
You've made tons of claims, Bob. Saying "it's better than x" doesn't cut the mustard. In what way? What specific value for which material property are you using in your comparison?
You've provided very few facts, and if you are either unable or unwilling to follow through, I will request this thread be moved to ATM.
It's not that difficult! Simply fill in the blanks of your super-material using SI units. You may find the requisite fields at this List of Materials Properties (http://en.wikipedia.org/wiki/List_of_materials_properties). The ones in which we're particularly interested in are the first three: Mechanical, Electrical, and Thermal.
Don't worry if you're unable to provide answers to all of them, particularly the thermal properties. Just give us what you have. Corrosion resistance and Reactivity would be nice, too, as would it's permeability.
This will help us to evaluate your claims from a rational, scientific basis rather than a wordy plethora of claims that it's better than sliced bread.
Thanks.

This is why I say this board has changed from its former pristine form. First, they want to restrict any mention of the topic to only this one thread. Then they want to ghettoize it further (in an attempt to make sure no one reads it) by moving it to the ATM subforum.
This board is now becoming like some other space oriented boards that attempt to restrict discussion of topics the moderators or some forum members don't like. Another way this has been done is by claiming some objections to the unpopular topic aren't addressed in order to claim the topic is ATM, when actually the objections were addressed, the responses were simply ignored.

I have given the links to the sites or articles that discuss the "brittleness" of diamond and to those that discuss the brittleness of commonly used materials in aerospace such as aluminum alloys and carbon fiber.

First of all, for diamond's material properties see here:

Material properties of diamond.
http://en.wikipedia.org/wiki/Material_properties_of_diamond

The tensile strength has actually been measured to be 60 GPa, though the theoretical strength extends up to 225 GPa. So the actual measured strength is already a hundred times better than steel and ten times better than the best carbon fiber.

The most often used quantity used to measure "brittleness" is fracture toughness. It's not given on that page for diamond's material properties. Fracture toughness has units of (megapascals)*(meters)^(1/2). Unfortunately, for this rather complicated unit of measurement, no simple name has been given (like a joule, a newton, a pascal, etc.):


Fracture toughness.
"In materials science, fracture toughness is a property which describes the ability of a material containing a crack to resist fracture, and is one of the most important properties of any material for virtually all design applications. It is denoted KIc and has the units of http://upload.wikimedia.org/math/e/d/0/ed082873dd47cc08d9456ef568e747a1.png.
The subscript 'Ic' denotes mode I crack opening under a normal tensile stress perpendicular to the crack, since the material can be made thick enough to resist shear (mode II) or tear (mode III).
Fracture toughness is a quantitative way of expressing a material's resistance to brittle fracture when a crack is present. If a material has a large value of fracture toughness it will probably undergo ductile fracture. Brittle fracture is very characteristic of materials with a low fracture toughness value."
http://en.wikipedia.org/wiki/Fracture_toughness

The team that has done the research on the new fast, easy, and cheap diamond manufacturing method gives the fracture toughness of natural diamond in the range of 8 to 10 on their web page, and assert their new synthetic diamond exceeds this:


"Ultratough Single-Crystal Diamond - The high quality, gem-size single
crystal diamonds at very high growth rate have tunable mechanical
properties. Vickers hardness tests were used to evaluate the hardness
and fracture toughness of these crystals. It was found that the
nominal fracture toughness of CVD diamonds grown under H2/CH4/N2
chemistry is around 15 ~ 20 MPa m1/2, with respect to 10 2 MPa m1/2
of Type Ib diamonds, and 8 4 MPa m1/2 of natural Ia and IIa
diamonds. Further enhancement in toughness was observed for single
crystal diamonds grown under newly developed chemistry; the fracture
toughness could be improved by at least a factor of two. No radical
fracture was observed around Vickers indentation craters, creating
difficulty in measuring this very high toughness. These new diamonds
could be used in new application in optics, electronics, and
mechanical applications. In particular, low cost tough and ultratough
CVD single crystal diamonds can play an important role in machining
and abrasive industries. [12]"
http://cdac.gl.ciw.edu/index.php?option=com_content&task=view&id=99&Itemid=40

Compare this to the values in this table from the "Fracture toughness" page:



Here are some typical values of fracture toughness for various materials:
===========================================
Material KIc (MPa-m1 / 2)
Metals
Aluminum alloy (7075) 24
Steel alloy (4340) 50
Titanium alloy 44-66
Aluminum 14-28
Ceramics
Aluminum oxide 3-5
Silicon carbide 3-5
Soda-lime-glass 0.7-0.8
Concrete 0.2-1.4
Polymers
Polymethyl methacrylate 0.7-1.6
Polystyrene 0.7-1.1
Composites
Mullite fiber reinforced-mullite composite 1.8-3.3 [1]
===========================================

Note that the research team on their web page said their new methods can increase
the fracture toughness of synthetic diamond to twice the previous values the synthetics had which were already in the range of 15 to 20 (above that of natural diamond.) This would mean their new methods creates synthetic diamond of fracture toughness in the range of 30 to 40. Indeed this is confirmed in their patent application:


(WO/2007/018555) ULTRATOUGH CVD SINGLE CRYSTAL DIAMOND AND THREE DIMENSIONAL GROWTH THEREOF.
...
"DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Reference will now be made in detail to the preferred embodiments of the present invention, the results of which are illustrated in the accompanying drawings.
[0026] The microwave plasma CVD-grown single-crystal diamond referred to in this application were grown with the apparatus described in U.S. patent application number 10/288,499, filed on November 6, 2002, now U.S. Patent No. 6,858,078, entitled "Apparatus and Method for Diamond Production," which is hereby incorporated by reference.
[0027] One embodiment of the invention includes a single-crystal diamond grown by microwave plasma chemical vapor deposition that has a toughness of at least about 30 MPa m1/2. In another embodiment, the toughness of the single-crystal diamond is at least about 35 MPa m1/2. In another embodiment, the toughness of the single-crystal diamond is at least about 40 MPa m1/2."
...
http://www.wipo.int/pctdb/en/wo.jsp?IA=US2005032199&DISPLAY=DESC

Note that fracture toughness for the new synthetic diamond in the range of 40 well exceeds the fracture toughness of the aluminum alloy listed in the table, which is a common one used in the aerospace industry.
And this far exceeds the fracture toughness of carbon fiber composites getting increasing use in aerospace. This article gives on p. 6 the fracture toughness of carbon fiber composites as only around 1 in these units:

Fracture Toughness Characterization of Carbon-Epoxy Composite using Arcan Specimen.
M. Nikbakht, and N. Choupani
PROCEEDINGS OF WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY.
VOLUME 31 JULY 2008 ISSN 2070-3740
http://www.waset.org/pwaset/v31/v31-128.pdf

The actual highly brittle nature of carbon fiber composites was illustrated in stark form by the Columbia accident since the reinforced carbon-carbon panels in the wing fractured on impact just from foam:

http://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Impact-test.jpg/800px-Impact-test.jpg


Bob Clark

Ara Pacis
2009-Jan-21, 09:10 PM
Could you please use the quote feature in the future and also not use hard returns except at the end of a paragraph? kthx

Also, links and quotes are meant to support arguments, not stand in for them. If you just post those with little of your own analysis it forces people to try to do your work for you, which they won't. Your posting style leads people's eyes to glass over and gives people headaches just to look at it and try to read it. Formatting conventions exist for a reason.

ravens_cry
2009-Jan-22, 05:23 AM
I wonder if super large industrial diamonds could, in theory anyway be used for the first time to make larger retractor telescopes then are possible in glass.
Just a thought.

nauthiz
2009-Jan-22, 05:44 AM
Your posting style leads people's eyes to glass over and gives people headaches just to look at it and try to read it.

Frankly, I'm surprised anyone's trying to read them anymore. To me they're just a pastiche of semirandom hunks of copy-and-pasted text with little to no indication of why they're being included (let alone why certain hunks of text keep re-appearing over and over) or what's the relevant thing to be looking for in them.

It doesn't help their case that these ASCII-bombs seem to largely get used as an alternative to actually responding to other people's comments. Such as, say, the observation that diamond is a rather brittle material.

Speaking of, I'd still like to know why that's not true. Or why it's not such a big problem for the proposed applications. Preferably in 10 sentences or less. Tensile strength isn't what I'm looking for, I'm more interested in things like the abovementioned Wikipedia article on diamonds' mention that they're brittle enough that you can shatter one with a hammer. (ETA: Resistance to shear, which I don't think has been mentioned yet, seems like it's probably the most important brittleness-related property for a lot of the applications have come up.)

cjameshuff
2009-Jan-22, 05:48 AM
I wonder if super large industrial diamonds could, in theory anyway be used for the first time to make larger retractor telescopes then are possible in glass.

Diamond has high dispersion. The telescope would be great for demonstrating chromatic aberration...it would otherwise be limited to imaging through narrow band-pass filters.

ravens_cry
2009-Jan-22, 06:47 AM
Diamond has high dispersion. The telescope would be great for demonstrating chromatic aberration...it would otherwise be limited to imaging through narrow band-pass filters.

Thanks for the information. Too bad, but maybe some other material equally strong yet better suited for use in telescopes will be found/invented.

cjl
2009-Jan-22, 07:35 AM
Diamond does have great thermal conductivity though - it would be an excellent heatsink material.

Nicolas
2009-Jan-22, 08:21 AM
Yes, but doesn't this artificial diamond start to act in unwanted ways already at quite low temperatures?

RGClark
2009-Jan-22, 01:07 PM
Frankly, I'm surprised anyone's trying to read them anymore. To me they're just a pastiche of semirandom hunks of copy-and-pasted text with little to no indication of why they're being included (let alone why certain hunks of text keep re-appearing over and over) or what's the relevant thing to be looking for in them.

It doesn't help their case that these ASCII-bombs seem to largely get used as an alternative to actually responding to other people's comments. Such as, say, the observation that diamond is a rather brittle material.

Speaking of, I'd still like to know why that's not true. Or why it's not such a big problem for the proposed applications. Preferably in 10 sentences or less. Tensile strength isn't what I'm looking for, I'm more interested in things like the abovementioned Wikipedia article on diamonds' mention that they're brittle enough that you can shatter one with a hammer. (ETA: Resistance to shear, which I don't think has been mentioned yet, seems like it's probably the most important brittleness-related property for a lot of the applications have come up.)

Maybe you should actually READ the copied links and then you would understand WHY they do answer the question of "brittleness".

As I said before, in attempts to disregard an unpopular topic a common method is to claim objections to the topic are unanswered when actually they are answered; the responses are simply ignored.


Bob Clark

RGClark
2009-Jan-22, 01:10 PM
Could you please use the quote feature in the future and also not use hard returns except at the end of a paragraph? kthx

Also, links and quotes are meant to support arguments, not stand in for them. If you just post those with little of your own analysis it forces people to try to do your work for you, which they won't.

What further do you want to know?

Bob Clark

RGClark
2009-Jan-22, 01:21 PM
New material testing is one of the fundamental R&D costs - even minor changes require complete validation of the manufacturing process, compatibility testing, aging, tensile properties, thermal properties, crack propegation - and there are few if any shortcuts: How do you quantify a year of Florida weathering in less than a year?

Any fundamentally new system of materials will require years of evaluation before they can be included in any rational manned program. Both of the Shuttle failures can be traced to poor or incomplete characterization of new materials. (O-ring design/sealing and insulation bonding at cold temperatures.)


A legitimate point. Diamond has undergone many decades of testing because of its remarkable physical properties. There are even entire journals devoted just to it.
You would have to confirm the properties that have been proven to hold in samples just a few millimeters across still hold for samples meters across.
That the research team able to create the centimeter size diamonds quickly, at low cost were able to demonstrate their methods can produce synthetic diamond that actually exceeds natural diamond in strength and hardness strongly implies that these qualities will be retained for meter size samples as well.


Bob Clark

RGClark
2009-Jan-22, 01:46 PM
Seconded - the use of artificial diamond as a building material or even aviation building material is ATM.

Experts on diamond research have stated the new manufacturing methods make perfect diamond at low cost possible.
To me what is unreasonable is to suppose a material a hundred times stronger than steel would only be used for making big, sparkly windows.



Bob Clark

nauthiz
2009-Jan-22, 03:00 PM
Maybe you should actually READ the copied links and then you would understand WHY they do answer the question of "brittleness".

As I said before, in attempts to disregard an unpopular topic a common method is to claim objections to the topic are unanswered when actually they are answered; the responses are simply ignored.

I wasn't meaning to say that the questions hadn't been answered at all. I was meaning to say that if they had been answered, they were probably missed by a lot of people because they were answered in the form of a giant muddle of rambling text that's very hard (at least for me) to translate back into meaningful thoughts. That's why I said 10 sentences or less. When I wrote that I felt the distinct feeling that somewhere in what I had just read there was a clear and simple thought trapped in there that was trying to get out.

I did read what you wrote. Twice. The first time my eyes glazed over and I didn't really follow where you were going with it (admittedly I was tired, but still). The second time the quote tags were added and that helped immensely, but I still came away with the feeling that you took two pages to get around to saying something that you could have communicated in a single sentence: "The team claims they should be able to produce diamonds with a fracture toughness approaching that of some titanium alloys."

mugaliens
2009-Jan-22, 06:46 PM
The actual highly brittle nature of carbon fiber composites was illustrated in stark form by the Columbia accident since the reinforced carbon-carbon panels in the wing fractured on impact just from foam...

And the actual highly brittle nature of diamonds has long been illustrated by how easy it is to shatter them with a simple blow from a hammer.

cjameshuff
2009-Jan-22, 07:21 PM
The actual highly brittle nature of carbon fiber composites was illustrated in stark form by the Columbia accident since the reinforced carbon-carbon panels in the wing fractured on impact just from foam:

This is getting ridiculous. That's a carbon-carbon composite. The fiber is carbon fiber, yes, but the matrix is graphite. It's not a high strength carbon fiber composite, it's a graphite ceramic that's not quite as near-uselessly fragile as plain solid graphite would be.

Single crystal diamond is also fragile. It has cleavage planes where the crystal will shear from a small impact. It has a completely different failure mode from metal alloys...a piece of metal might deform slightly, get dented, even permanently bend. A similar diamond part would remain pristine up until it shattered. Individual graphite fibers fail in the same way, but it occurs to individual graphite fibers, not to the bulk material, making composites far more durable.

This technology is a major advance, but mainly for thin coatings, tools, optical components, and semiconductor heat sinks (and possibly semiconductors themselves). Diamond is not the one perfect supermaterial you make it out to be. It's dense, it cleaves and shatters, it's hard to work, it's impossible to weld or glue, and it burns.

If you were in an automobile accident in a diamond vehicle, you would likely be sliced and diced by the resulting fragments. If the vehicle remained intact and had the weight savings you claim, it would absorb very little of the impact energy through deformation, the passenger cabin would decelerate to a stop almost instantaneously, and you would impact against the interior at nearly the full velocity the vehicle was moving at. The car might still be usable once you hose it out, but that's not going to be a strong selling point.

Ara Pacis
2009-Jan-22, 11:27 PM
What further do you want to know?

Me, not much. I'm just reading and waiting for other experts to explain things, but thought I would point out issues in the meta-discussion.


Maybe you should actually READ the copied links and then you would understand WHY they do answer the question of "brittleness".

The point that we are trying to get across is that you should read the links so that you can explain them and demonstrate that you understand the questions and your proffered answers. It's more than just pointing to links and saying "I'm right until you prove me wrong."

This is a discussionboard, not StumbleUpon. If all you want to do is list links without discussion, then consider your job here done.

nauthiz
2009-Jan-23, 06:07 AM
This is getting ridiculous. That's a carbon-carbon composite. The fiber is carbon fiber, yes, but the matrix is graphite. It's not a high strength carbon fiber composite, it's a graphite ceramic that's not quite as near-uselessly fragile as plain solid graphite would be.

Ah, thanks for explaining. I was wondering about that - my car-freak brother's carbon fiber body panels certainly don't seem to shatter every time they're hit by a piece of foam.

eburacum45
2009-Jan-23, 11:13 AM
The stongest material that can be made from carbon is probably this one;
http://en.wikipedia.org/wiki/Aggregated_diamond_nanorods
we are a long way from making this material in bulk.

When and if this material becomes available in bulk it might offer all the advantages that RGClark expects from bulk diamond; but that day is a long way off.

slang
2009-Jan-23, 11:57 AM
Ah, thanks for explaining. I was wondering about that - my car-freak brother's carbon fiber body panels certainly don't seem to shatter every time they're hit by a piece of foam.

Although, in fairness, your brother's car won't get hit by foam while it is travelling at Mach 2.46 (1,870 miles per hour or 840 metres per second, source (http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster)).

nauthiz
2009-Jan-23, 03:00 PM
Although, in fairness, your brother's car won't get hit by foam while it is travelling at Mach 2.46 (1,870 miles per hour or 840 metres per second, source (http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster)).

Fair enough. That was a stronger impact than I had remembered - half a kilogram traveling at 240 m/s probably does hit just a wee bit harder than your average speck of gravel.

mugaliens
2009-Jan-23, 05:31 PM
This is a discussionboard, not StumbleUpon. If all you want to do is list links without discussion, then consider your job here done.

I second that, and would add: "...and ours, as well."

RGClark
2009-Jan-23, 06:02 PM
Fair enough. That was a stronger impact than I had remembered - half a kilogram traveling at 240 m/s probably does hit just a wee bit harder than your average speck of gravel.

To be more precise, you have to make a distinction between the speed the shuttle was moving at and the relative speed of the foam to the vehicle when it impacted (estimated from video of the event.)
That wikipedia source gives the impact speed of the foam as 800 ft/sec about 545 mph.


Bob Clark

RGClark
2009-Jan-26, 07:22 PM
Just saw this on the http://www.bautforum.com/space-exploration/83970-skyloop-variant-skyhook.html thread:

http://nextbigfuture.com/2009/01/industrial-scale-production-of.html

It reports on making a "Skyhook" using newly produced strong fibers composed of carbon nanotubes:

http://nextbigfuture.com/2009/01/cambridge-making-carbon-nanotubes.html

What's especially interesting is a $1,000,000 prize offered for ultra strong fibers these new carbon nanotube composites may satisfy:

Tether Strength Competition.
http://www.spaceward.org/elevator2010-ts

However, a fiber made of synthetic diamond produced using the new fast, easy, and cheap manufacturing method would be twice as strong as these and well within the strength requirements of the tether strength competition, so eligible for the $1 million dollar prize.


Bob Clark

nauthiz
2009-Jan-26, 07:26 PM
To be more precise, you have to make a distinction between the speed the shuttle was moving at and the relative speed of the foam to the vehicle when it impacted (estimated from video of the event.)
That wikipedia source gives the impact speed of the foam as 800 ft/sec about 545 mph.

. . . or about 240 meters per second. ;)

mugaliens
2009-Jan-27, 10:00 PM
To date, you have ignored the engineering considerations. Despite numerous requests for clarification of your many claims, you post nothing but links to sites discussing well-known properties of diamond, which do not support your many claims.

Admins/mods, please move this to ATM.

RGClark
2009-Jan-29, 12:50 PM
To date, you have ignored the engineering considerations. Despite numerous requests for clarification of your many claims, you post nothing but links to sites discussing well-known properties of diamond, which do not support your many claims.

Admins/mods, please move this to ATM.

This is what they call a "troll". Its intent is to start an argument.
Understandable that many people can't believe a technological change of transformational importance is in the offing. It's called "future shock".
No matter. It will become clear when universities worldwide start making golf ball sized diamonds in a day. Then when undergrads see how easy it is, such large sized diamonds will start being made in people's basements. That the diamond will retain it's hardness and strength properties even at these large sizes will make it's importance for construction materials obvious.
Another way it's importance in construction will become obvious is the fact it can win the $1 million dollar tether competition prize:

Tether Strength Competition.
http://www.spaceward.org/elevator2010-ts

Here are the requirements from the site:



Tether Length: 2 m (closed loop)
Tether Weight: 2 g
Breaking Force: 1 ton, 1.5 ton (approx)
Prize Purse: $900k, $1.1M

Best performance to date: 0.72 Ton
Number of Teams: None Yet
Competition Date: February-March, 2009 (tentative)

Now, calculate the width of a diamond cable required to lift 1 metric ton, assuming 60 GPa tensile strength of diamond. You'll find the volume required for a 2 meter cable at this width can fit into a cube 1 cm on a side. In other words the centimeter-sized synthetic diamond created by the Carnegie team is already enough to win the million dollar competition!
It wouldn't be a trivial matter though fitting this cube into a cable at this thinness (less than a millimeter wide). Perhaps it could be cut by laser in a spiral pattern so that the entire volume gets turned into a ribbon less than a millimeter wide. There is the problem of doing it this way though that diamond is stiff (actually it's the stiffest material known.) Conceivably this could still work since for example glass is normally stiff but when produced in the form of micron wide fibers (fiberglass) it is quite flexible.
Another possibility would be to cut off very many straight segments of the desired width. A very important and useful aspect of the Carnegie teams method is that you can grow larger diamond on already produced diamond. This may mean that you won't have to have one large microwave generator to get a large diamond. You could grow small diamonds separately using small generators. Then join the separate diamonds together by using their CVD process between adjacent sides of diamonds placed close together. So to win the tether competition you might be able to join all the thin segments cut off the 1 cm diamond by using the Carnegie teams method to produce a diamond joining interface between the separate segments.


Bob Clark

Swift
2009-Jan-29, 02:28 PM
Everybody chill or this thread will be closed. If you want to discuss diamond as an engineering material, discuss it. If you are tired of the discussion, stay out of the thread. If you think there is a bad post, report it (red triangle), but no name calling and finger pointing.

cjameshuff
2009-Jan-29, 08:22 PM
Understandable that many people can't believe a technological change of transformational importance is in the offing. It's called "future shock".

Everybody's focusing on fullerene, graphene carbon, and various newly-developed polymers instead of an improved variation on a decades-old method of producing diamond because of future shock? Have you even considered that it might instead be that your knowledge is lacking? To all appearances, you have just been flat out ignoring everything that doesn't agree with your preconceptions.



No matter. It will become clear when universities worldwide start making golf ball sized diamonds in a day. Then when undergrads see how easy it is, such large sized diamonds will start being made in people's basements. That the diamond will retain it's hardness and strength properties even at these large sizes will make it's importance for construction materials obvious.

It's not that easy! People have been actively researching CVD diamond processes since the 1980s! It requires special equipment and finely controlled conditions...this isn't shake-and-bake! Thick, quickly grown films tend to have internal strain problems, a golfball sized chunk of rapidly grown diamond would likely be riddled with cracks, if it doesn't spontaneously shatter during growth, and would take a week to produce at the fastest achieved growth rate. We might see a hobbyist making diamond coatings sometime soon, maybe even incorporating techniques developed by the Carnegie team, but growing macroscopic diamond crystals is not a trivial exercise.



Now, calculate the width of a diamond cable required to lift 1 metric ton, assuming 60 GPa tensile strength of diamond. You'll find the volume required for a 2 meter cable at this width can fit into a cube 1 cm on a side. In other words the centimeter-sized synthetic diamond created by the Carnegie team is already enough to win the million dollar competition!

No, it's not. It's nowhere close to a 2 meter long cable. The only thing it has in common is volume...I can get closer with cotton thread.

Glass is nowhere near as stiff as diamond, and has no cleavage planes. Diamond has perfect octahedral cleavage, its lattice naturally shears cleanly along planes corresponding to the faces of an octahedron. "Spiral cutting" a piece of diamond into a ribbon isn't going to work, neither is "gluing" many tiny pieces. A continuously produced ribbon is likely to be polycrystalline, with weaker connections between the crystal grains, and if it's monocrystalline, it's still likely that the lattice orientation will be less than optimal or even vary across the ribbon, leading to a significantly weaker cable (possibly by a factor of more than 200).

Look at the Carnegie team's own list of applications: infrared and x-ray transparent windows, diamond anvils, semiconductors, abrasive or wear resistant machine parts...diamond anvils come closest to your claims, and they are carefully designed with the cleavage planes taken into account to avoid destroying the diamonds. They carefully apply pressure to precisely shaped and aligned diamonds, relying mostly on the material's hardness. They don't advertise it as a universal wonder material, because they know it isn't one.

Swift
2009-Jan-29, 08:47 PM
Just to add to cjameshuff's thoughts.... I've looked at the CVD diamond work on and off for years. The company I worked for about ten years ago, had discussions about such work with John Angus (http://www.case.edu/cse/eche/faculty_angus.html)from CWRU on his diamond film work. My feeling was that if diamonds ever found widespread use, it would be as thin films, not bulk materials. It seemed that one of the great limitations was that the substrates that they could be coated onto (and adhere) were very limited. Come up with a good process for diamond coating steel or aluminum metal, and you might have something interesting.

RGClark
2009-Jan-30, 12:53 AM
Everybody's focusing on fullerene, graphene carbon, and various newly-developed polymers instead of an improved variation on a decades-old method of producing diamond because of future shock? Have you even considered that it might instead be that your knowledge is lacking? To all appearances, you have just been flat out ignoring everything that doesn't agree with your preconceptions.
...

The overwhelmingly important fact here is that the new manufacturing method can make the diamond in bulk sizes.
The Carnegie Institution research team is one of the leading teams in all of high pressure research, diamond research and CVD research. If they say their new process can make large scale diamond possible at low cost, experts in the field tend to take that very seriously:



Diamonds: a dime a dozen.
A new way to create diamonds could change the world.
Shannon Paulus
Science and Technology Writer
"A team of geophysicists at the Carnegie Institution for Science is perfecting a cheap way to create large diamonds. In his paper, “On the way to mass-scale production of perfect bulk diamonds,” published in Proceedings of the National Academy of Sciences, Alexander Zaitsev stated that the method could cause a technological revolution.
'A profound impact of this innovation on industry (electronics, optics, thermal management, precise cutting), medicine (diamond scalpel surgery), and jewelry (cheap large brilliants) is difficult to overestimate,' he wrote."
http://www.mcgilldaily.com/article/6230-diamonds-a-dime-a-dozen

I agree with you that when nanotubes and graphene also can be made in bulk sizes that also will be overwhelmingly important. I also happen to believe that that will also become possible in the very short term.
Look, I'm making some pretty specific assertions. I'm saying within a year university lab produced macroscale diamond will be routine. And that the first tests of its use for construction purposes will also occur within a year.
If that doesn't happen within just a year then I will have been wrong. But I think its possible importance will be so obvious to material scientists that investigations for construction purposes will proceed quite soon, if they haven't already.



Bob Clark

WalrusLike
2009-Jan-30, 01:46 AM
... Look, I'm making some pretty specific assertions. ....

Bob I hope that you are correct. But I would bet that it gets caught by that pesky devil-in-the-details.

I am still waiting for the home print-anything machine that was going to revolutionise production by using ink-jet technology to build 3d composite components and machinery from free public domain plans.

Or all those leisure hours that robots would be providing me with. Or traffic jams gone because flying cars will use 3d space rather than 2d.

This sounds promising, but I wouldn't bet the house on it just yet. Good luck to them (and subsequently, us).

RGClark
2009-Jan-30, 08:37 PM
...
No, it's not. It's nowhere close to a 2 meter long cable. The only thing it has in common is volume...I can get closer with cotton thread.

Glass is nowhere near as stiff as diamond, and has no cleavage planes. Diamond has perfect octahedral cleavage, its lattice naturally shears cleanly along planes corresponding to the faces of an octahedron. "Spiral cutting" a piece of diamond into a ribbon isn't going to work, neither is "gluing" many tiny pieces. A continuously produced ribbon is likely to be polycrystalline, with weaker connections between the crystal grains, and if it's monocrystalline, it's still likely that the lattice orientation will be less than optimal or even vary across the ribbon, leading to a significantly weaker cable (possibly by a factor of more than 200).
...

Carbon nanotubes have stiffness as measured by elastic modulus about the same as diamond yet they can be bent without breaking:

Nanotech Advance Makes Carbon Nanotubes More Useful.
http://www.jacobsschool.ucsd.edu/uploads/news_release/2005/magick_Right-angle.nanotubes.jpg
"UCSD researchers exploited the strong alignment of nanotube growth with the direction of electric field lines to create tailor-made bends."
http://www.jacobsschool.ucsd.edu/news_events/releases/release.sfe?id=368



Carbon nanotubes.
http://www.3rdtech.com/images/small_vs_large_bendsweb.jpg
"The stress test: One experiment repeatedly bent a nanotube through contortions to see if it would break. All these modifications were performed by the NanoManipulator, with the user guiding the AFM tip by moving the Phantom force-feedback pen."
http://www.3rdtech.com/carbon_nanotubes.htm

These nanotubes had a ratio of length to width of about 1,000 to 1. So for diamond of similar stiffness to the nanotubes to likewise be bent, we would expect the width for a 2 meter cable to be say 2 mm or smaller.

The tensile strength of natural diamond is commonly given as 60 GPa. But this quoted number doesn't say what direction it is being measured in. Its theoretical strength ranges from 90 GPa in the weakest direction to 225 GPa in the strongest. Moreover, the new CVD method can produce diamond of 50% greater hardness than natural diamond, which very likely translates into greater tensile strength as well. Then it is conceivable that the new superhard CVD diamond would retain sufficient strength in all directions to serve as a cable to win the "tether" competition.

Note also that the method of growing the diamond from a seed particle is much different than just "glueing". The single crystalline form is continued on indefinitely by this microwave plasma CVD process. So much so that the newly grown diamond is indistinguishable from a single crystal natural diamond. And as I said after annealing the new diamond can be significantly stronger than a natural diamond. In regards to joining up separate segments cut off from the 1 cm wide CVD diamond, the only question would be is it possible to align the two segments so that the crystalline pattern continues smoothly from one segment to the other. My suggestion is it would work if the crystalline structures of the sides facing each other were aligned to within nanometric precision.

I suggested these two methods because at the rate of 150 microns/hour it would take months to make a diamond cube 2 meters across. However, if you read the Carnegie teams reports they expect to scale up their process to produce larger diamond by using greater microwave power. Indeed prior research with CVD methods suggests the growth rate should scale approximately linearly with applied power. Then you could use instead a microwave generator of 10 times the power to 60 kwatts to reduce the time by a factor of 10.
However, a more interesting possibility is suggested by the fact that this growth on the plane surfaces of the seed diamond is scaling actually linearly with applied power. This strongly implies that if instead of directing the 6 kwatts now used to all the sides of a seed particle millimeters across, we concentrated this to a single face of a particle only a few microns across then we could increase the growth rate many times, and might cut the required time for a cable 2 meters long but only microns wide to just a few days.


Bob Clark

cjameshuff
2009-Jan-30, 10:48 PM
The overwhelmingly important fact here is that the new manufacturing method can make the diamond in bulk sizes.

No, the overwhelmingly important fact is that diamond isn't the material you think it is! It's not being disputed that they can be made, what's being disputed is your wild and nonsensical claims about what their manufacture means!



Carbon nanotubes have stiffness as measured by elastic modulus about the same as diamond yet they can be bent without breaking:

Those nanotubes are in a relaxed state. They are not being bent by an applied force, they are simply not straight.

Single carbon nanotubes are also limited to a few tens of nm across, limiting the strain that results from bending, are composed of a hollow structure which can buckle rather than fracturing to relieve strain, and lack cleavage planes. A solid diamond tether is not comparable. Bending forces cause strains roughly proportional to the thickness of the material, which together with the stiffness will quickly cause forces that exceed the strength of the material as thickness is increased. Large sheets of glass flex as well, but if the bend radius exceeds a certain amount, they shatter.

The thin cross section will give it little to resist bending forces with. It would probably snap just from contact with any hard edge, I would not be surprised if your hypothetical tether couldn't be handled by hand. A composite tether composed of microscopically thin fibers or films would be a far more appropriate comparison, but is little closer to being produced than one using nanotubes.



In regards to joining up separate segments cut off from the 1 cm wide CVD diamond, the only question would be is it possible to align the two segments so that the crystalline pattern continues smoothly from one segment to the other. My suggestion is it would work if the crystalline structures of the sides facing each other were aligned to within nanometric precision.

Your suppositions about the achievable strength have no basis in hard data, you once again ignore the issues of the cleavage planes and brittleness, and...you're talking about seamlessly joining crystal lattices at the atomic level. The Carnegie team is not doing this. Your tether does not exist, nor does a way of producing it. Nanotubes are at least being grown in oriented forests and formed into highly organized films and threads.

Seamlessly joining crystals isn't even what you want to do. It means fractures will propagate across the crystal planes, meaning the ribbon will be as brittle as if it were grown in one piece. Polycrystalline diamond won't be as strong as a single crystal, but it won't fail this way. This is what makes aggregated diamond nanorods and ultrahard fullerite tougher than single-crystal diamond.



However, a more interesting possibility is suggested by the fact that this growth on the plane surfaces of the seed diamond is scaling actually linearly with applied power. This strongly implies that if instead of directing the 6 kwatts now used to all the sides of a seed particle millimeters across, we concentrated this to a single face of a particle only a few microns across then...

...you would likely get a chamber full of powdered graphite, amorphous carbon etc. Some of it might even be fused into a solid mass. It almost certainly wouldn't be a clean, ultra-perfect mono-crystal diamond ribbon. What possible basis do you have to think that you can just boost the power per unit area to achieve multiple orders of magnitude increase in growth with no drawbacks? If it were that simple, why have they been struggling to get even 100 nm/s growth rates? If it were that easy, with the same equipment, they could just quarter the linear dimensions of the seed and quadruple their reported growth rates.

mugaliens
2009-Jan-31, 06:11 PM
The thin cross section will give it little to resist bending forces with. It would probably snap....

I hear you, cjameshuff. But I'm an engineer. Most of the non-engineers here are objective and well-educated enough to grasp these simple fundamentals.

By his own admission, though, rcclark isn't familiar with the engineering aspects. Thus, his enthusiasm for the concept has been overpowering any objectivity he may have had. Arguing with him is useless.

He's simply not listening.

You've given him all the info he needs, but he's either not considering it, or he doesn't possess the education required to consider it. He could probably look up the term "shear modulus" (or modulus of rigidity), but would probably be overimpressed with diamond's 478 GPa compared to steel's 79.3 GPa, thinking that's somehow "better," without realizing the downsides, such as how easily it's factured, or understanding why titanium, with a modulus of just 41.4 GPa, half that of steel, is used in aerospace applications instead of steel (and aluminum's is even less, at 25.5).

Keep trying, though. At least others are listening. :)

RGClark
2009-Jan-31, 06:33 PM
No, the overwhelmingly important fact is that diamond isn't the material you think it is! It's not being disputed that they can be made, what's being disputed is your wild and nonsensical claims about what their manufacture means!

...

Actually you did rather imply it wouldn't work to scale the Carnegie methods to large scale while maintaining single crystalline form.
Let's suppose the process does scale up to say meter scale at low cost. Materials scientists who work in construction or aerospace try to wring every last bit of strength out of the materials they have at hand.
You think if they see a meter sized block of material that has been proven to be a hundred times better than steel in both tensile strength and compressive strength that they won't try to use it for construction purposes?


Bob Clark

RGClark
2009-Jan-31, 06:53 PM
I hear you, cjameshuff. But I'm an engineer. Most of the non-engineers here are objective and well-educated enough to grasp these simple fundamentals.

By his own admission, though, rcclark isn't familiar with the engineering aspects. Thus, his enthusiasm for the concept has been overpowering any objectivity he may have had. Arguing with him is useless.

He's simply not listening.

You've given him all the info he needs, but he's either not considering it, or he doesn't possess the education required to consider it. He could probably look up the term "shear modulus" (or modulus of rigidity), but would probably be overimpressed with diamond's 478 GPa compared to steel's 79.3 GPa, thinking that's somehow "better," without realizing the downsides, such as how easily it's factured, or understanding why titanium, with a modulus of just 41.4 GPa, half that of steel, is used in aerospace applications instead of steel (and aluminum's is even less, at 25.5).

Keep trying, though. At least others are listening. :)

No. I just think material scientists and engineers who work specifically in high strength materials are more creative than you think they are.
Keep in mind that concrete is overwhelmingly important in construction yet is barely better than glass in fracture resistance. Diamond is a thousand times stronger than concrete, and the Carnegie process can make synthetic versions of diamond at least 40 times as fracture resistant.
And glass fiber, which is of course highly brittle, used in the form of fiberglass is second only to carbon fibers for use in high strength composites:

Glass-reinforced plastic.
http://en.wikipedia.org/wiki/Glass-reinforced_plastic

It's not like I'm saying this going to come to light 10 to 20 years from now. You'll know within a year if it's valid.


Bob Clark

mugaliens
2009-Jan-31, 10:22 PM
You think if they see a meter sized block of material that has been proven to be a hundred times better in both tensile strength and compressive strength that they won't try to use it for construction purposes?

No, RGClark, they won't, as there are other properties of both diamond and other materials which make the other materials FAR more suitable for most purposes, including the ones you keep touting, wrongly, as problems in need of a diamond solution.

Unfortunately, you're to enamored (obsessed) with this diamond idea of yours that you're either unwilling or incapable of listening to reason, and keep posting your hodgepodge of wishful thinking mush.

Diamonds are great as both abrasive material and heat conductors. And they're pretty, with one of the highest refractive indices of any gem, if not the highest.

But for the applications you keep touting?

No, RGClark - Diamonds aren't a guy's best friend.

RGClark
2009-Feb-04, 01:14 PM
In another thread I said the technological changes due to the widespread availability of diamond in bulk sizes will be like the difference between the Stone Age and the Iron Age. That may be a bit extreme. It might be closer to the difference between the Bronze Age and the Iron Age.
Still that in itself is extremely worrisome. It frequently happens than an extreme change in technical knowledge is accompanied by increased knowledge in war making, and this has been known to create disastrous results.
This is quite famously expressed in that transition from the Bronze Age to the Iron Age:



Bronze Age collapse.
The Bronze Age collapse is the name given by those historians who see the transition from the Late Bronze Age to the Early Iron Age, as violent, sudden and culturally disruptive, expressed by the collapse of palace economies of the Aegean and Anatolia, which were replaced after a hiatus by the isolated village cultures of the Dark Ages period of history of the Ancient Near East.
...
Anatolia.
Every site important during the preceding Late Bronze Age shows a destruction layer, and it appears that here civilization did not recover to the same level as that of the Hittites for another thousand years. Hattusas, the Hittite capital, was burned and abandoned, and never reoccupied. Karaoglan was burned and the corpses left unburied. Troy was destroyed at least twice, before being abandoned until Roman times.
...
Greece.
None of the Mycenaean palaces of the Late Bronze Age survived, with destruction being heaviest at palaces and fortified sites. Up to 90% of small sites in the Peloponnese were abandoned, suggesting a major depopulation. The End Bronze Age collapse marked the start of what has been called the Greek Dark Ages, which lasted for more than 400 years. Other cities, like Athens, continued to be occupied, but with a more local sphere of influence, limited evidence of trade and an impoverished culture, from which it took centuries to recover.
...
Conclusion.
Robert Drews describes the collapse as "the worst disaster in ancient history, even more calamitous than the collapse of the Western Roman Empire".[2] A number of people have spoken of the cultural memories of the disaster as stories of a "lost golden age". Hesiod for example spoke of Ages of Gold, Silver and Bronze, separated from the modern harsh cruel world of the Age of Iron by the Age of Heroes.

Nature and causes of destruction.
As part of the Late Bronze Age-Early Iron Age Dark Ages, it was a period associated with the collapse of central authorities, a general depopulation, particularly of highly urban areas, the loss of literacy in Anatolia and the Aegean, and its restriction elsewhere, the disappearance of established patterns of long-distance international trade, increasingly vicious intra-elite struggles for power, and reduced options for the elite if not for the general mass of population.
...
http://en.wikipedia.org/wiki/Bronze_Age_collapse

This article surprised me. I had always thought that for instance the conquest of Bronze Age societies by Iron Age cultures was just because iron made better weapons. But this article suggests that is not really the case (at least not for the type of iron available then), so there is some debate about why these Bronze Age civilizations collapsed. One explanation is that iron ores were more readily available so the iron weapons became more readily available to those with the knowledge to create them.

I have argued that the widespread availability of diamond in bulk sizes will result in routine space access to most of the nations of the world. This in itself of course will be a problem that has to be addressed for defense issues.
However, an even bigger problem may also be produced. It may be that the wide spread availability of such an ultra hard, strong material will also make weapons of mass destruction more easy to produce. This potentially could have consequences as serious as the transition from the Bronze Age to the Iron Age.
However, knowing about it now might give us some options about how to plan for it and prevent the type of disastrous consequences that occurred during a previous "Age".

I had some ideas about how it might be prevented. However, the proposals are well outside what has been done so far. Since this thread has already been criticized as bordering on science fiction I'll post those ideas to the ATM forum.



Bob Clark

mugaliens
2009-Feb-04, 09:02 PM
It might be closer to the difference between the Bronze Age and the Iron Age.

I would agree with that.


Still that in itself is extremely worrisome. It frequently happens than an extreme change in technical knowledge is accompanied by increased knowledge in war making, and this has been known to create disastrous results.

You just contradicted yourself, downgrading a routine change from Stone Age to Iron Age to a minor change from Bronze Age to Iron Age. Then you intimate it's "an extreme change."


...so there is some debate about why these Bronze Age civilizations collapsed. One explanation is that iron ores were more readily available so the iron weapons became more readily available to those with the knowledge to create them.

Another explanation is that they, like all the other stone, bronze, iron, steel, and space age civilizations that have collapsed did so for other reasons unrelated to an age transformation.


I have argued that the widespread availability of diamond in bulk sizes will result in routine space access to most of the nations of the world.

Yes, you have indeed argued that. Yet you have not managed to convince anyone (or at least not many), despite the fact that you're in the company of forward thinkers who'd love to embrace "the next best thing." The problem is, this technology isn't "the next best thing." It's interesting, and will find it's way into some neat applications, but it's not going to solve the space lift dillemma.


It may be that the wide spread availability of such an ultra hard, strong material will also make weapons of mass destruction more easy to produce.

ultra hard, strong materials have absolutely nothing to do with weapons of mass destruction. You aren't even grasping at straws, here. This is the stuff of pure fiction, and wildly non-scientific fiction, at that.


This potentially could have consequences...

No.


...knowing about it now might give us some options about how to plan for it and prevent the type of disastrous consequences that occurred during a previous "Age".

PLAN TO PREVENT DISASTEROUS CONSEQUENCES FROM MASS-PRODUCED DIAMONDS:

STEP 1: Embrace reality, wherein one learns that mass-produced diamonds do not lead to "disasterous consequences."

STEP 2: Repeat step 1, as required.


Since this thread has already been criticized as bordering on science fiction I'll post those ideas to the ATM forum.

Thank you.

RGClark
2009-Feb-04, 09:54 PM
ultra hard, strong materials have absolutely nothing to do with weapons of mass destruction. You aren't even grasping at straws, here. This is the stuff of pure fiction, and wildly non-scientific fiction, at that.




There is a connection. And those in the weapons community would know what it is.
But it's not something that should be discussed on a public forum.

Bob Clark

RGClark
2009-Feb-04, 09:59 PM
You just contradicted yourself, downgrading a routine change from Stone Age to Iron Age to a minor change from Bronze Age to Iron Age. Then you intimate it's "an extreme change."

Another explanation is that they, like all the other stone, bronze, iron, steel, and space age civilizations that have collapsed did so for other reasons unrelated to an age transformation.

That Wikipedia article rather intimated that there is a disagreement about the fact of Bronze Age civilization collapse on interaction with cultures with Iron Age weapons. But no serious historian disputes this fact.
The fact that such conflicts caused the collapse of the Bronze Age cultures is proof it is a serious change, as is the fact that historians do still consider them to be so significantly different as to ascribe to them separate "Ages".


Bob Clark

RGClark
2009-Feb-04, 10:09 PM
Yes, you have indeed argued that. Yet you have not managed to convince anyone (or at least not many), despite the fact that you're in the company of forward thinkers who'd love to embrace "the next best thing." The problem is, this technology isn't "the next best thing." It's interesting, and will find it's way into some neat applications, but it's not going to solve the space lift dillemma.

You are an engineer so undoubtedly you have friends outside your own specialization.
I'll make a deal with you. If you can find a materials engineer who specializes specifically in strength of materials who will say on this forum he would have no interest in using for construction purposes meter or larger size synthetic diamond that has been proven to have the same or better strength and hardness as natural diamond, then I'll never post on this topic on this forum again.


Bob Clark

Ara Pacis
2009-Feb-05, 02:51 PM
Wait, did you just hijack your own thread about diamonds with a post about anthropology? :)

nauthiz
2009-Feb-05, 03:09 PM
I might have missed it, but how are these diamonds going to be worked? Wouldn't it be prohibitively expensive to drill the holes through diamond parts so you can bolt them together?

RGClark
2009-Feb-05, 06:23 PM
I might have missed it, but how are these diamonds going to be worked? Wouldn't it be prohibitively expensive to drill the holes through diamond parts so you can bolt them together?

The Carnegie team has used lasers to carve diamonds in rounded shapes:

Scientists Are Producing Bigger CVD Diamonds Faster
(May 17, '05, 5:21 Edahn Golan)
http://www.idexonline.com/image_bank/image_folders/Tech/Carnegie_diamonds_fig_3a.jpg
"12 mm (1/2 inch) 5 carat diamond laser
cut from a 10 carat single crystal produced
by high-growth rate CVD. The diamond
was laser cut (and inscribed) from a
diamond block and only partially polished."
http://www.idexonline.com/portal_FullNews.asp?id=24041

I suggested in regards to producing a diamond cable, that possibly separate diamond pieces could be joined by using the CVD process to produce a smooth connecting diamond interface between the separate pieces.
In a review paper, the Carnegie team mentions that this is a method being tried by some other teams for creating large diamonds:

Growing Diamond Crystals by Chemical Vapor Deposition.
Russell J. Hemley, Yu-Chun Chen, and Chih-Shiue Yan.
Elements, vol. 1, p. 105-108, March 2005
"Potential solutions for producing larger area CVD
diamonds include use of a mosaic or tile arrangement of
several {100}-surfaced diamond seeds (Kobashi et al. 2003),
3-dimensional growth on multiple {100} faces, and enlargement
of each surface (FIG. 3A)."
http://www.elementsmagazine.org/archives/e1_2/e1_2_art_hemley.pdf



Bob Clark

mugaliens
2009-Feb-05, 10:22 PM
There is a connection.

No.


And those in the weapons community would know what it is.

I am in the weapons community. The answer remains no.


But it's not something that should be discussed on a public forum.

The only relation between diamonds and mass casualties has to do with conflict diamonds (http://pawss.hampshire.edu/topics/conflictdiamonds/index.html), also called blood diamonds, where hundreds of thousands have died. The diamonds themselves, however, aren't the weapons (knives and guns are).

There's nothing classified about it.

There are, however, applications for diamonds to be used in countering WMDs...

But that's not classified, either:

diamond sensors detect biological agents (http://news.medill.northwestern.edu/chicago/news.aspx?id=113589&print=1)

RGClark
2009-Feb-06, 01:11 AM
No.

I am in the weapons community. The answer remains no.



The manufacturing details of such weapons is not something commonly discussed publicly.
I'll let that go.

Bob Clark

Ara Pacis
2009-Feb-06, 05:14 AM
Yeah, yeah, yeah... is it supposed to be part of the design or part of the fabrication process? I suppose I could look up the neutron cross section and see if that suggests anything, but I'm too lazy.

mugaliens
2009-Feb-06, 12:47 PM
I'll let that go.

I won't.

I'm very well versed in certains fields. In some, you might call me a "SME." In others, "instructor." Still others, "operator."

I can think of several applications where your wonderously large, maginificant, and seemingly magical diamonds might be applicable. Yet they are not finding applicability in those areas, and certainly nothing in WMD, at least on the application side. In the defense side, I've already posted an area where they're finding use.

Look, Bob - if you're going to hint at something, follow through with something substantial.

If you can't follow through because something is classified, then you should not be hinting.

If it's not classified, then I find this "bait and switch" behavior of your reflective of your many previous posts, mostly fluff and promises, with little substantive comment.

RGClark
2009-Feb-06, 01:02 PM
If you can't follow through because something is classified, then you should not be hinting.

If it's not classified, then I find this "bait and switch" behavior of your reflective of your many previous posts, mostly fluff and promises, with little substantive comment.

OK. You're not convinced. But just like I said material scientists who work specifically in strength of materials would be convinced, so also would be those scientists who work specifically in the field I'm referring to.


Bob Clark

RGClark
2009-Feb-06, 01:05 PM
Yeah, yeah, yeah... is it supposed to be part of the design or part of the fabrication process? I suppose I could look up the neutron cross section and see if that suggests anything, but I'm too lazy.


I don't advise that. When one looks at the possibilities for the beneficial effects of the Carnegie teams advance, one wishes also more people had the "altruism" gene.


Bob Clark

nauthiz
2009-Feb-06, 02:10 PM
OK. You're not convinced. But just like I said material scientists who work specifically in strength of materials would be convinced, so also would be those scientists who work specifically in the field I'm referring to.

That doesn't impress me. That's just playing coy, which does the opposite of impress me. What is the application you're suggesting?

cjameshuff
2009-Feb-06, 02:30 PM
Yeah, yeah, yeah... is it supposed to be part of the design or part of the fabrication process? I suppose I could look up the neutron cross section and see if that suggests anything, but I'm too lazy.

Almost twice the density of graphite, diamond could make more compact neutron reflectors. Given his...enthusiasm about the material, he may even be under the impression that a diamond tamper would hold together longer by enough time to be significant. Even if that's not what he's thinking...it would make a good reflector/tamper material (or at least, better than graphite), and considering the cost of producing U-235/Pu-239, it may not be too expensive. Hardly a world-ending revolution, though.

Aside from that, maybe he's thinking of superdiamond tanks of metallic deuterium and tritium for fusion devices, something that'd go along with some of his wilder claims. Or maybe he's got some strange idea relating to implosion devices and the compressive strength of diamond...

RGClark
2009-Feb-06, 05:04 PM
Almost twice the density of graphite, diamond could make more compact neutron reflectors. Given his...enthusiasm about the material, he may even be under the impression that a diamond tamper would hold together longer by enough time to be significant. Even if that's not what he's thinking...it would make a good reflector/tamper material (or at least, better than graphite), and considering the cost of producing U-235/Pu-239, it may not be too expensive. Hardly a world-ending revolution, though.

Aside from that, maybe he's thinking of superdiamond tanks of metallic deuterium and tritium for fusion devices, something that'd go along with some of his wilder claims. Or maybe he's got some strange idea relating to implosion devices and the compressive strength of diamond...

I don't know, but I don't think finding better and easier ways to make the most dangerous weapons we have available is something humanity should be focusing on. We already have enough weapons to wipe out humanity many times over. Finding better ways of making them so that every nation would have their own supply, so that now we can wipe ourselves out a factor of 10 larger number of times is a worthless activity.


Bob Clark

Ara Pacis
2009-Feb-07, 06:07 AM
I don't know, but I don't think finding better and easier ways to make the most dangerous weapons we have available is something humanity should be focusing on. We already have enough weapons to wipe out humanity many times over. Finding better ways of making them so that every nation would have their own supply, so that now we can wipe ourselves out a factor of 10 larger number of times is a worthless activity.


Bob Clark

Are you now suggesting easier/simpler fabrication and materials synthesis techniques instead of device design? Better centrifuges I suppose?

mugaliens
2009-Feb-07, 09:48 PM
OK. You're not convinced.

So long as you keep posting nonsense, I will remain unconvinced. Nor is it your job to convince me. If anything, we've been trying to educate you on science and engineering principles, but to date, you've avoided all attempts, and have steadfastly clung to your wild, pie-in-the-sky claims which violate the known laws of physics. You have interesting ideas, to be sure, and it would be nice if they held up under scrutiny.

But they don't.


But just like I said material scientists who work specifically in strength of materials would be convinced, so also would be those scientists who work specifically in the field I'm referring to.

Several such individuals have posted here, and they've labeled your claims as unsubstantiated and contrary to to what we do know of materials science, including the recent advances in growing large diamonds.

Enjoy the rest of your weekend.

RGClark
2009-Feb-08, 01:45 PM
Are you now suggesting easier/simpler fabrication and materials synthesis techniques instead of device design? Better centrifuges I suppose?

The story is told of Alfred Nobel who when he found out from a premature obituary that he would only be known as the man who made modern warfare possible decided to institute the prizes that bear his name, including the Nobel Peace Prize.
What would you rather be known as the person who made possible World War III or the person who prevented it from happening?


Bob Clark

RGClark
2009-Feb-08, 01:52 PM
Several such individuals have posted here, and they've labeled your claims as unsubstantiated and contrary to to what we do know of materials science, including the recent advances in growing large diamonds.


Not those who work specifically in strength of materials.
You don't ask electricians to design your plumbing and you don't ask plumbers to design your electrical work.


Bob Clark

nauthiz
2009-Feb-08, 05:00 PM
What would you rather be known as the person who made possible World War III or the person who prevented it from happening?

I'll grant I'm neither an expert on nuclear weapons nor international politics, but I have a hard time believing that the development of a material that makes a better neutron reflector is going to cause a massive increase in nuclear proliferation, World War III, etc.

It's not like it suddenly makes it possible to build a bomb using crud scraped off the faces of glow-in-the-dark wristwatches or anything like that.

Swift
2009-Feb-08, 05:46 PM
Not those who work specifically in strength of materials.
You don't ask electricians to design your plumbing and you don't ask plumbers to design your electrical work.


Bob Clark
I'm not sure that's the right analogy.

I don't have a speciality in strength of materials. But I have worked in materials science for 25 years. I'm unconvinced that very large synthetic diamonds on a production scale are that close to realization. And while such technology would have interesting applications, I'm unconvinced that they would be as revolutionary as you believe.

But, I'm quite content to sit back and see what happens.

mugaliens
2009-Feb-08, 10:35 PM
Not those who...

Yes. Those.

Ara Pacis
2009-Feb-09, 09:10 AM
What would you rather be known as the person who made possible World War III or the person who prevented it from happening?


Bob Clark

As the one who won it. WWIII is already possible.

RGClark
2009-Feb-09, 09:29 AM
As the one who won it. WWIII is already possible.

This is getting too political.
I think we'll just agree WWIII should be avoided.

Bob Clark

RGClark
2009-Feb-12, 02:40 PM
I'm not sure that's the right analogy.

I don't have a speciality in strength of materials. But I have worked in materials science for 25 years. I'm unconvinced that very large synthetic diamonds on a production scale are that close to realization. And while such technology would have interesting applications, I'm unconvinced that they would be as revolutionary as you believe.

But, I'm quite content to sit back and see what happens.


May 16, 2005
Very Large Diamonds Produced Very Fast.
Washington, D.C. Researchers at the Carnegie Institution’s Geophysical Laboratory have learned to produce 10-carat, half-inch thick single-crystal diamonds at rapid growth rates (100 micrometers per hour) using a chemical vapor deposition (CVD) process. This size is approximately five times that of commercially available diamonds produced by the standard high-pressure/high-temperature (HPHT) method and other CVD techniques. In addition, the team has made colorless single-crystal diamonds, transparent from the ultraviolet to infrared wavelengths with their CVD process.
...
To further increase the size of the crystals, the Carnegie researchers grew gem-quality diamonds sequentially on the 6 faces of a substrate diamond plate with the CVD process (Fig. 2).
http://www.carnegieinstitution.org/diamond-13may2005/diamonds_fig_2.jpg
Figure 2. Single-crystal diamond block formed by deposition on 6 {100} faces of a substrate diamond, such as the 4 x 4 x 1.5 mm3 crystal shown below.
By this method, three-dimensional growth of colorless single-crystal diamond in the inch-range (~300 carat) is achievable.
Finally, new shapes have been fabricated with the blocks of the CVD single crystals. Figure 3 shows a 12-millimeter anvil that can be used for new types of scientific experiments.
The standard growth rate is 100 micrometers per hour for the Carnegie process, but growth rates in excess of 300 micrometers per hour have been reached, and 1 millimeter per hour may be possible. With the colorless diamond produced at ever higher growth rate and low cost, large blocks of diamond should be available for a variety of applications. “The diamond age is upon us,” concluded Hemley.
http://www.carnegieinstitution.org/news_releases/news_0505_16.html

The 10 carat diamonds they have made so far, cut and polished, are worth in the range of a few 10's to hundreds of thousands of dollars. But they say here in this 2005 article they expect to make 300 carat diamonds. These in cut and polished form would be worth in the 10's of millions of dollars range.



New Process Promises Bigger, Better Diamond Crystals.
ScienceDaily (Oct. 28, 2008) — Researchers at the Carnegie Institution have developed a new technique for improving the properties of diamonds—not only adding sparkle to gemstones, but also simplifying the process of making high-quality diamond for scalpel blades, electronic components, even quantum computers.
...
"The most exciting aspect of this new annealing process is the unlimited size of the crystals that can be treated. The breakthrough will allow us to push to kilocarat diamonds of high optical quality" says coauthor Ho-kwang Mao.
http://www.sciencedaily.com/releases/2008/10/081027174541.htm

Now, this would be going into a whole new stratosphere. A kilocarat size diamond would be in the range of 10 centimeters across. Diamonds of this size at current prices would be worth in the range of billions of dollars:


Golden Jubilee Diamond.
Weight 545.67 carats (109.13 g)
Color Yellow-Brown
Cut Fire Rose Cushion
Country of origin South Africa
Mine of origin Premier Mine
Date discovered 1985
Cut by Gabi Tolkowsky
Original owner De Beers
Current owner King Bhumibol Adulyadej of Thailand
Estimated value USD 1.5 billion
http://en.wikipedia.org/wiki/Golden_Jubilee_Diamond

The Carnegie team while making such a diamond would have to have armed guards protecting it while it is being made and round-the-clock guards afterwards as well.
This in itself would be a revolutionary change in the diamond market that diamonds this size could be made at will. Because of their expertise in this arena, you have to take the claim this could be possible seriously. If they succeed, then there would be little doubt that meter size diamonds also become possible.


Bob Clark

RGClark
2009-Feb-12, 02:55 PM
Yes. Those.

There are two separate questions involved here. First, is it possible to make meter size diamonds at low cost while maintaining their single crystal form. And secondly, would scientists involved in strength of materials research want to use such diamonds for construction purposes, assuming the synthetics did maintain or exceed the strength and hardness of natural diamonds.
Most of the debate on this thread has been about the second question. Knowing the near obsessive dedication of such scientists towards getting materials at high strength and low weight, I think it is almost axiomatic that they would investigate how such diamonds could be used for these purposes.


Bob Clark

djellison
2009-Feb-12, 03:15 PM
You are making the entirely false assumptions that

a) People would pay as much for artificial diamonds as they would for natural ones (They won't)

b) That availability of these large diamonds wouldn't devalue diamond as an asset (They will)

After all - you're going on about building skyscrapers out of diamond - you can't do that when it's $10B for a brick - rendering the cost of a building greater than all money ever earned, spent or printed in all history.

RGClark
2009-Feb-12, 03:30 PM
You are making the entirely false assumptions that

a) People would pay as much for artificial diamonds as they would for natural ones (They won't)

b) That availability of these large diamonds wouldn't devalue diamond as an asset (They will)

After all - you're going on about building skyscrapers out of diamond - you can't do that when it's $10B for a brick - rendering the cost of a building greater than all money ever earned, spent or printed in all history.

I agree with you that if made in such sizes, diamonds would be immensely devalued probably to be comparable to other construction materials.
The overwhelmingly important technological advances to made completely overshadow the fact that it would lead to the collapse of the diamond industry.
Keep in mind also, that so far, these single crystal CVD diamonds are indistinguishable from natural diamonds.


Bob Clark

NEOWatcher
2009-Feb-12, 03:37 PM
I agree with you that if made in such sizes, diamonds would be immensely devalued probably to be comparable to other construction materials.
I doubt it would go that far. There's even some traditional building material are out of reach of normal construction projects. I can't think of any right now. Can marble be artificially made? I don't see a lot of marble being used.

The overwhelmingly important technological advances to made completely overshadow the fact that it would lead to the collapse of the diamond industry.
I would tend to agree with that statement. I'm not sure the diamond industry is one that a particularly think is very important on a global scale.

The question though, after diamonds are so inexpensive and common, what do you buy your wife without being called cheap?

mugaliens
2009-Feb-12, 08:00 PM
These in cut and polished form would be worth in the 10's of millions of dollars range.

No, Bob. They won't. Simple law of supply and demand. If you dramatically increase the supply, the going price will drop like a carbon mineralized rock.

The alternative would be to "educate" the market about real and artificial diamonds, equating the artificial ones as only slightly better than cubic zirconium.

"Wow! That's a nice rock! Is it real, or one of those artificial diamonds?"

"Yes, it's artificial."

"[wandering off]Oh... [/wandering off]"


Diamonds of this size at current prices would be worth in the range of billions of dollars...

No, Bob. If deBeers isn't successful in stratifying real and artificial diamonds, the introduction of such arbitrarily large diamonds would result in worldwide diamond prices per carat falling through the floor, the demise of deBeers, and the collapse of the worldwide diamond industry, including blood diamonds.

That would unsettle some hotspots...

Swift
2009-Feb-13, 03:31 AM
OK, so the Carnegie Institution’s Geophysical Laboratory had this ability in 2005. But that doesn't prove the ability on a production scale. If these large diamonds are going to be used as a building material, such that they revolutionize the world, then someone has to produce them on the ton scale and at a cost that is comparable to other building materials (with possibly an appropriate allowance for improved properties). I have seen no evidence of this.

There have been lots of cool materials that seemed revolutionary in the lab, but for various technical or economic reasons, could not be scaled up to a commercial scale. I think it remains to be seen if this is so for large diamonds.

publiusr
2009-Feb-13, 10:50 PM
Compromise. Glassy steels may need a little bit of Carbon re-intoduced to act like molecular rebar, and the diamond nanorods might be the key. How about diamond deposition upon such a glassy stell, with composite wrappings on the outside and a more flexable lining on the inside.

A good Sea Dragon Core?

nauthiz
2009-Feb-14, 04:45 PM
There have been lots of cool materials that seemed revolutionary in the lab, but for various technical or economic reasons, could not be scaled up to a commercial scale. I think it remains to be seen if this is so for large diamonds.

I'm still waiting for my buckyball bike lube.

mugaliens
2009-Feb-15, 01:55 AM
I'm still waiting for my buckyball bike lube.

They made a ton of it, but it slipped away... :cry:

loglo
2009-Feb-15, 05:05 AM
snip

If deBeers isn't successful in stratifying real and artificial diamonds, the introduction of such arbitrarily large diamonds would result in worldwide diamond prices per carat falling through the floor, the demise of deBeers, and the collapse of the worldwide diamond industry, including blood diamonds.

That would unsettle some hotspots...

Maybe the price of diamonds would come down so much they will be sold by the kilo as opposed to the current obscure unit. :)

Ara Pacis
2009-Feb-15, 07:51 AM
Why not custom order a diamond grown with certain inclusions to have a name or a face inscribed inside of it? That might keep the price up... for a little while. Until they have them on 24-hour wait at Walmart.

mugaliens
2009-Feb-15, 11:29 PM
Or online...

publiusr
2009-Feb-20, 07:10 PM
I think that early on, a hydrogen explosive bolt filled with liquid oxygen, might flash away as steam. This might make for nice link and pin sets ups that might help bolt catchers reduce debris--with attachment points turning to water vapor.

neilzero
2009-Dec-06, 09:02 PM
Tantalum is likely about as costly as silver. Hafnium perhaps more costly than gold. That limits tantalum hafnium carbide as a superior replacement for graphite in very high temperature applications.
Diamond will likely have a few applications in the climber for the Edwards type space elevator, but likely cannot replace CNT = carbon nano tubes for the ribbon = tether, because diamonds are great in compression but do not stretch well, nor handle shocks well. Neil

Hop_David
2009-Dec-07, 03:11 AM
The question though, after diamonds are so inexpensive and common, what do you buy your wife without being called cheap?

A ring with an authentic moon rock.

If diamonds become inexpensive and cheap enough to use in every day appliances or packaging, we might have a heck of a trash problem. I expect diamonds are even less biodegradable than most of our troublesome garbage.

Antice
2009-Dec-07, 05:43 AM
A ring with an authentic moon rock.

If diamonds become inexpensive and cheap enough to use in every day appliances or packaging, we might have a heck of a trash problem. I expect diamonds are even less biodegradable than most of our troublesome garbage.

well.. sort off. but diamonds are easy to destroy.
heating them up above a certain point makes them loose their crystalline structure.
this makes them easy enough to recycle in the diamond manufacturing process.
however. I'd not expect to see them used as an everyday packaging material. the reason is that the processes with witch they may be made are pretty energy intensive. they will never be as cheap as say plastics.

swampyankee
2009-Dec-09, 11:24 AM
Diamonds are useful in manufacturing, as they're hard. My father, who was a toolmaker, had a fairly large collection of diamond-tipped drill bits and cutters in his personal tool chest.

I think that optical-quality diamond film, with its hardness, would be a great material for coating eyeglass lenses. Making eyeglass lenses out of optical diamond might be better, but I suspect that diamond isn't resilient enough to survive US-required impact resistance tests.

cjameshuff
2009-Dec-09, 07:05 PM
I think that optical-quality diamond film, with its hardness, would be a great material for coating eyeglass lenses. Making eyeglass lenses out of optical diamond might be better, but I suspect that diamond isn't resilient enough to survive US-required impact resistance tests.

Diamond is high density and high dispersion, not qualities you want in eyeglass lenses, but the high IOR makes up for the high dispersion (diamond has an Abbe number of 55, while most eyeglass plastics are in the low 30s) and would allow thinner lenses that would make up somewhat for the density. Resilience...if diamond faces can be sandwiched onto a thin plastic core, it shouldn't be a problem. Just something to prevent cracks from propagating through, or to hold things together if they do.

Antice
2009-Dec-09, 08:26 PM
covering the lenses with ultra hard coatings is already done. it's not diamond but the optical qualities of the stuff they use is way better than diamond anyhow. in all aplications where diamond materials are to replace an existing material one has to keep the economic aspect in view. diamond is not going to be cheap to manufacture. ever. it takes a LOT of energy do do it. no matter what method you use.

swampyankee
2009-Dec-10, 01:13 AM
covering the lenses with ultra hard coatings is already done. it's not diamond but the optical qualities of the stuff they use is way better than diamond anyhow. in all aplications where diamond materials are to replace an existing material one has to keep the economic aspect in view. diamond is not going to be cheap to manufacture. ever. it takes a LOT of energy do do it. no matter what method you use.

My experience with scratch-resistant coatings for eyeglass lenses would not tend to support their being "ultra-hard." I am careful with my lenses (my glasses cost way too much for me to abuse them), but the useful life of my lenses tends to be constrained by their surfaces being scratched. A harder coating would be nice, and a few microns of diamond my be just the ticket.

I suspect relatively consumer products would benefit from the structural or optical properties of large diamonds, except for oddments like the crystals in a chandelier. Diamonds are already used quite extensively in grinding and cutting tools, and as windows in various types of scientific equipment. Diamond semiconductors may become useful in a few years (I'm not holding my breath; GaAs hasn't exactly dethroned silicon).

Of course, a few decades ago aluminum was hideously expensive. Nobody would have ever dreamt of using it to make beverage containers.

Now, diamond coinage would be interesting. Obviously, it would not be produced by stamping.