| 摘要 |
PURPOSE:To obtain a corrosion-resistant Si3N4 sintered compact, comprising Si3N4 and an additive containing a sintering assistant containing a Ce component at a specific weight ratio to the additive expressed in terms of oxides and having a prescribed density by making the Ce component present in the grain boundary phase. CONSTITUTION:This silicon nitride sintered compact comprises 60-99wt.% Si3N4 and 40-1wt.% additive containing a sintering assistant having 0.1-1.0 weight ratio of a Ce component expressed in terms of oxide [CeO2/(CeO2 +X)] (X is the weight of the additive component other than Ce expressed in terms of the oxide) and >=90% relative ratio to the theoretical density and further contains the Ce component present in the grain boundary phase. Furthermore, this method for producing the Si3N4) sintered compact is to add a solvent to Si3N4 powder and a sintering assistant comprising a Ce component such as CeO2 and one or more of Mg, Ca, Al, Zr, Hf, Y and other rare earth elements or oxides, nitrides and carbides thereof, mix and pulverize the resultant mixture, prepare a slurry, dry the slurry, then temporarily form the mixed powder with a uniaxial press, etc., then regularly form the temporarily formed compact with a cold isostatic working press and further sinter the compact in a nonoxidizing atmosphere under >=0.1MPa pressure. |
