Re: New Material Harder Than Diamond

"manofsan@xxxxxxxxx" wrote:
>
> Here's something I read a few days back:
>
> http://physicsweb.org/articles/news/9/8/16/1?rss=2.0
>
> It's about a new carbon material that's harder than diamond. It seems
> to be obtained by compressing fullerene carbon at extreme pressure.
>
> Just a few questions, if anyone cares to answer:
>
> How is it possible for carbon material to be harder than the diamond
> lattice? Isn't that lattice the ideal geometric shape for hardness
> purposes?
> Can one assume this new material will be comparable in brittleness to
> diamond?
>
> They briefly say that the process could be scaled up for
> industrial-scale production. Will it only be possible to make this
> material in bulk using the extreme pressure? When we see diamond-coated
> razorblades and other diamond-coatings in consumer products, will the
> manufacturing process for this new harder material allow for coating it
> onto things?
>
> Is the manufacturing process likely to be significantly more expensive
> than for industrial diamond manufacturing?

The definition of "hardness" is prone to grantology. The disordered
nature of the created diamondoid lattice pins dislocations. It is
also 3% denser than diamond. Reworking CVD diamond under geodynamic
conditions gives a tougher, harder diamond, too. Black sintered
polycrystalline diamond is "harder" than diamond in engineering
applications for its being tough rather than brittle.

Process scale up for the new stuff is ludicrous. A standard sintered
diamond press costs about $1 million and cycles in 20 minutes. The
hyper-exotic press used in the "breakthrough" will not scale to
industrial production. It's also difficult to see how the expensive
buckeyball feed can result in a competitive product. Industrial
diamond abrasive is around $1./gram tops. Hourglasses filled with
diamond dust are given away as industry awards.

Nanotubes were very exotic. It required a decade to refine their
chemistries to create them as a bulk product at not unreasonable
cost. The new "diamonnd" is not a matter of chemistry but of
engineering. If there is a way to cheat on a phase diagram, it hasn't
yet been found.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
.