| 摘要 |
PURPOSE:To improve abrasion resistance of silicon nitride sintered compact without lowering toughness by specifying decreasing ratio of Si content of surface part to Si content of inside. CONSTITUTION:Si3N4 powder having about 0.6mum average particle size is blended with a powder of Al2O3, AlN, etc. and the blend is molded to afford a molded article. Then the molded article is heated at 1,500-1,800 deg.C by ordinary pressure sintering method, etc., so that Si3N4 of part in plural mum-0.1mm thickness of surface of the molded article is vaporized and sintered so that Si decreasing ratio shown in the calculation formula is >=20wt.% to produce the Si3N4 sintered compact. |
