We have developed a new type of near net shape sintering process using nitridation of Si and other inorganic powders. In this report, the sintering property of powder mixture compacts of TiC (10μm or 0.9μm) and Si (0.9μm) in a nitrogen atmosphere at 1350°C was investigated.
A large portion of the Si formed Si3N4 on reaction with nitrogen, while TiC formed TiN and free carbon. A small portion of this free carbon was converted into β-SiC on reaction with Si and about 98% of the free carbon remained in the sintered body. Thus, composite ceramics having a composition of Si3N4·TiC·TiN·C·β-SiC were obtained. The porosity of this composite was much smaller than that of ordinary Si3N4 bonded ceramics, because of the large volume expansion for formation of free carbon. The pore size under 5μm can be got using TiC powder with an avarage size of 0.9μm.