Effect of atmosphere on weight loss in sintered silicon carbide during heat treatment

Heat treatment was performed on beta -SIC with different sintering additive s in the temperature range 1873-2073 K, in both argon and nitrogen-gas atmo spheres. In the case of the specimens heat-treated at 2073 K in argon, the weight loss was more than the total weight of the sintering additives, exce pt for B,C-doped beta -SIC. On the other hand, weight loss was suppressed b y about one-third to one-half in nitrogen gas. Weight loss depended mainly on the reaction at the interface between the SiC grains and the grain-bound ary phase.