| 摘要 |
PURPOSE:To obtain a high-density sintered silicon nitride body which has sufficient high-temp. strength even at ordinary pressure and low-temp. calcination and is available as a high-temp. structural material by adding a specified sintering auxiliary contg. cordierite as a main component to silicon nitride powder, pulverizing, mixing and molding the mixture and sintering this molded body. CONSTITUTION:A sintering auxiliary consisting of cordierite, aluminum oxide and rare earth elemental oxide is added to silicon nitride powder and the mixture is pulverized, mixed and molded and thereafter this molded body is sintered at 1450-1650 deg.C to obtain a high-density sintered silicon nitride body. Cordierite close to theoretical composition (13.8wt.% MgO, 34.8wt.% Al2O3, 54.4wt.% SiO2) is preferably utilized and as rare earth elemental oxide, Y2O3 is preferably utilized. As the composition rate of the sintering auxiliary, cordierite is 10-60% and rare earth elemental oxide is regulated to 1-3 pts.wt. for 1 pts.wt. Al2O3. The amount of the sintering auxiliary is regulated to 10-40wt.% of a total of the mixture. |
