Abstract: A bearing material of silicon carbide particularly useful for application in the hot water field is provided having improved corrosion resistance under increased thermal stresses wherein the bearing material is characterized by a predominantly course-grained silicon carbide matrix of pressureless sintered silicon carbide having a biamodal grain sized distribution wherein the biomodal grain size distribution is formed by from 50 to 90% by volume of prismatic, tabular, silicon carbide crystallites having a length of from 100 to 1500 .mu.m and from 10 to 50% by volume of prismatic tabular silicon carbide crystallites having a length of from 5 to <100 .mu.m.

Abstract: The invention relates to bearing materials of porous SiC having a trimodal pore composition and also a process for their production.The porous bearing material of pressureless-sintered SiC having from 3 to 10% by volume of independent closed pores having a trimodal pore composition consisting of micropores (M), fiber-shaped macropores (F) and spherical macropores (S), where the amounts in the pore system F-M-S (FIG. 1) are fixed by the trapezoidal area having the corner pointsa=10%M-80%F-10%Sb=10%M-10%F-80%Sc=40%M-10%F-50%Sd=40%M-50%F-10%Sand the micropores have a diameter of less than or equal to 5 .mu.m and the fiber-shaped macropores have a diameter of less than or equal to 30 .mu.m and a length of less than or equal to 80 .mu.m and the spherical macropores have a diameter of less than or equal to 70 .mu.m, and have a flexural strength of at least 250 MN/m.sup.2.