SILICON CARBIDE BASED, POROUS STRUCTURAL MATERIAL BEING HEAT−RESISTANT AND SUPER−LIGHTWEIGHT

摘要

A silicon carbide based, porous structural material being heat−resistant and super−lightweight; and a method for preparing the material, which comprises impregnating a spongy skeleton of a porous structure with a slurry containing a resin and a silicon powder to such an extent that open−cells of the porous structure are not closed, carbonizing the impregnated skeleton under vacuum or in an inert atmosphere at 900 to 1320˚C, subjecting the resultant carbonized porous structure to a reaction sintering under vacuum or in an inert atmosphere at 1320˚C or higher, to thereby form silicon carbide having good wettability with molten silicon and also generate open pores resulting from a volume reducing reaction, and impregnating the resultant porous structure with molten silicon under vacuum or in an inert atmosphere at 1300 to 1800˚C. The silicon carbide based material retains a form of a spongy porous stricture and can be prepared with ease by using the method.