Investigation of the Structure and Physicomechanical Characteristics of Reaction-Sintered Materials B.sub.4C-SiC

A composite material based on the B.sub.4C-SiC system with different initial carbon contents was obtained by reaction sintering (impregnation of a porous billet with liquid silicon). Carbon reacted with silicon to form a secondary silicon carbide that filled the space in the porous workpiece until a monolithic material was obtained. Boron carbide acted as the source of carbon if it was initially absent or its content was low. The obtained materials had the following characteristics: bending strength up to 320 MPa, density up to 2.85 g/cm.sup.3, microhardness up to 30 GPa.