| 摘要 |
PURPOSE:To obtain the silicoln nitride-based sintered body having superior strength at high temp. by sintering silicon nitride and specified sintering aid and limiting the grain size of the silicon nitride grains, the average thickness and the max. thickness of the grain boundary phase in the sintered body. CONSTITUTION:This silicon nitride-based sintered body consists of 80-99.9wt.% silicon nitride and 0.1-20wt.% sintering aid based on one of Eu2O3, Ge2O3, Tb2O3, Dy2O3, HO2O3, Er2O3, Tm2O3, Yb2O3, or Lu2O3 and has <=30mum average grain size of the silicon nitride grains, <=1.5mum average thickness and <=2mum max. thickness of the grain boundary phase. Since the sintering aid is a grain boundary forming component, in the case of >20wt.% sintering aid, the thickness of the grain boundary is increased and the strength of the sintered body is reduced. In the case of <0.1wt.% sintering aid, it is difficult to sinter silicon nitride, a high density sintered body in not obtd. and strength is reduced. |
