| 摘要 |
PURPOSE:To obtain a silicon nitride-based sintered body having superior wear and chipping resistances at high temp. in a well-balanced state and optimum for a tool. CONSTITUTION:This silicon nitride-based sintered body for a tool consists of 8wt.% oxide of a rare earth element, 10wt.% aluminum oxide, <=8wt.% at least one selected among hafnium oxide, hafnium nitride, hafnium carbide, hafnium silicide, hafnium boride and solid solns. of such compds. and the balance silicon nitride with inevitable impurities, has superior wear and chipping resistances at high temp. in a well-balanced state and gives a tool capable of maintaining long service life because the wear and chipping resistances are not extremely deteriorated. |
