| 摘要 |
PURPOSE:To obtain the titled ceramics having a high rupture toughness value and superior strength at high temp. by adding powder of TiN or metallic Ti to Si3N4 powder in combination with Y2O3, Al2O3 or the like as an additive for sintering and by sintering the resulting powdery mixture. CONSTITUTION:Si3N4 powder is mixed with Y2O3, Al2O3 or the like as an additive for sintering and simultaneously powder of TiN or metallic Ti or fine particles of TiO2 or the like which is converted into TiN or metallic Ti during sintering are added to prepare a powdery mixture. This mixture is sintered at about 1,780 deg.C under about 300kg/cm<2> pressure for about 90min to obtain the titled ceramics made of an Si3N4-additive type sintered body contg. 2-30wt.% fine grains of TiN or metallic Ti dispersed in the second phase of the grain boundary and in the Si3N4 grains. |
