Reactions in the Si_3N_4-TiN system containing Y_2O_3

摘要

During the sintering of composite material Si_3N_4-TiN, Y_2O_3 was used, in a concentration of 10% as the additive for densification. The reactions taking place between TiO_2 and Si_3N_4, as well as between Y_2O_3 and SiO_2 were followed. Thermal treatment was performed at 1780℃, with varying soaking time. It was found that TiO_2 reacts with Si_3N_4 whereby TiN and SiO_2 were formed. Moreover, SiO_2 reacts with Y_2O_3 giving Y-silicate as a reaction product. The composition of the Y-silicate varied with the variaton of TiN content in the composite. The chemical processes detected, are discussed from the point of view of their role in the densification of the system under study.