stiff composites for machine construction

While pondering the virtue of granite in an epoxy matrix as a machine
structural material, I shifted gears and started thinking about silicon
carbide in some sort of matrix.
SiC has great advantages over granite and almost all other structural
materials:
1. stiffness (high)
2. density (low)
3. thermal expansion (low)
4. specific heat (high)
5. mechanical and chemical stability (high)
6. cost (low)


It can be made into composites with epoxy or by filling up aluminum with it.
Possibly the internal damping would be high in the composite.

It would be interesting to calculate the relative merits of SiC/aluminum and
tungsten carbide as a boring bar.

A great deal of the mass of a machine tool is there to resist the stress and
vibration of the cutting forces, a superior structural material could reduce
this weight dramatically. Those of us who want desktop mills and lathes
would benefit.

I know of the SiC/Aluminum mix being used for telescope mirrors, does anyone
know of other structural uses for it?

Elliot B.