| 摘要 |
PURPOSE:To improve high-temperature strength and oxidation resistance of sintered beta-sialon produced by adding Al2O3, AlN and Y2O3 as adjuvants to Si3N4, by including a specific crystalline solid solution in the raw materials. CONSTITUTION:Si3N4 powder having an average particle diameter of 1.0mum is used as a raw material powder, added with an adjuvant consisting of powdery Al2O3, AlN and Y2O3 and mixed in wet state in ethanol. The mixture is dried, compression-molded and calcined to form a sintered article. The formed sintered material of beta-sialon contains a crystalline solid solution expressed by formula 2Y2O3.Siz-xAlxNz-xO1+x (0<x<2). Since the solid solution is stable at a high temperature, the obtained sintered beta-sialon has improved high-temperature strength. Furthermore, the crack generation caused by oxidization reaction at high temperature or low temperature can be prevented resulting in the improvement in the oxidation resistance at high and low temperature. |
