ガス圧焼結によるYb4Si2O7N2結晶相を有する窒化ケイ素の作製
2001 年 109 巻 1269 号 p. 453-456
詳細
2001 年 109 巻 1269 号 p. 453-456
Silicon nitride containing Yb2O3 as a sintering additive was gas-pressure sintered. A dilatometric study indicates that the liquid formation temperature of this additive is higher than that of commonly used additives. The material containing 3.6mol% of additive densified up to 99% of the theoretical density by sintering at 1950°C for 4h. The grain boundary phase of this material crystallized as Yb4Si2O7N2. The bending strength of this material was 460MPa at room temperature. This value is rather low because of voids formed during gas pressure sintering in the specimens. However, strength degradation at high temperature was limited because of the highly refractory Yb4Si2O7N2 grain boundary phase.
