Influence of Sintering Aids on the Sintering and Conductivity Properties of Si_3N_4 Composites

摘要

Silicon nitride (Si_3N_4) is one of the most important engineering materials. Due to its low self-diffusion coefficient at high temperature, Si_3N_4 is very hard to be densified without sintering aids. In the present work, the Y_2O_3 and light rare-earth oxides of La series (La_2O_3, CeO_2, Pr_2O_3, Sm_2O_3) and AlN, Al_2O_3, MgO, CaCO_3 were chosen to be sintering aids. Their effect on the sintering of Si_3N_4 composites was studied. The results showed that, among all of additives examined, Y_2O_3 is the best sintering aid and Y_2O_3-La_2O_3-A1N ternary composition was the best formula.