SLS Silicon Carbide

I've been wondering if anyone in the RepRap community has considered Silicon Carbide as a sintering material for 3d printing. I've seen academic papers showing that it's possible at the small scale [1], but it might be impressive to upscale the technology. The raw material is reasonably available (it's used as a sand-blasting agent industrially, and for traditional sintering). It seems to require inert gas shielding, but not specific pressures, and the laser power requirements might be met with a cheap diode laser.

SiC has some theoretically-impressive mechanical properties (high strength, low density, and high thermal conduction), but is brittle (it's a ceramic), and good structural performance might demand extreme purity both before and after sintering.

Existing work that I've read [1] suggests layer thicknesses on the 5um scale: does the community have the technology to work on this fine of a scale? Does anyone have any thoughts on any of this?

[1] http://utwired.utexas.edu/lff/symposium/proceedingsArchive/pubs/Manuscripts/2006/2006-32-Streek.pdf
[2] http://www.utwired.engr.utexas.edu/lff/symposium/proceedingsArchive/pubs/Manuscripts/2003/2003-43-Klocke.pdf

... with diode-lasers the best focus is around 50 to 100 microns in diameter and the processing depth is defined by wavelength, optical power and the particle size of the powder.

My different IR-diodes have 808 or 975nm and max. powers of 1W to 25W but will have problems melting white ceramics, as they will reflect most energy ... here dark coloured ceramic dust will act much better.

Another diode has 1W at 445nm wavelength, what's better absorbed by ceramics, but the power of 1W is something poor.

With my fiber-laser I'll have max. 50W at 1070nm and smallest focus diameter of around ten microns, so enough energy to sinter any material, but hadn't built a setup with inert gas until now ... this will take a bit more time ...

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Viktor
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Solid reaction using activated carbon, boron, and silicon powder as reactants.

I'd also be quite interested to see if anyone has any information or insight into the potential of this as suggested by "pch" above.