| 摘要 |
PURPOSE:To obtain Si3N4 sintered body which is excellent in self-lubricity and rolling service life, etc., by adding the specified amount of a sintering adjuvant to the mixture of Si3N4 powder and BN powder and molding the obtained mixture and covering the molded body with glass material and performing hot isostatic pressing therefor. CONSTITUTION:Both the raw material powder of silicon nitride and the raw material powder of boron nitride are mixed so that both are preferably regulated to a range of 80/20-99.5/0.5 by weight ratio. Then 20-2wt.% sintering adjuvant (e.g. a mixture of SrO, MgO and CeO2) is added to 80-98wt.% obtained mixture powder and mixed and thereafter this mixture is molded. Then this molded body is covered by glass material and thereafter a silicon nitride sintered body is obtained by performing hot isostatic pressing for this covered molded body. The obtained silicon nitride sintered body has excellent self-lubricity and therefore is effectively utilized in such the high-temp. environment that utilization of lubricating oil is made difficult or in the high-corrosion environment. |
