| 摘要 |
PURPOSE:To improve the high-temp. strength by calcining a mixture of AlN powder and SiO2 powder to obtain an AlN polytype powder in which SiO2 is dissolved in AlN, forming the powder and sintering the formed body in a nonoxidizing atmosphere. CONSTITUTION:The SiO2 powder having >=10m<2>/g BET specific surface is added by 10-20% to the AlN powder contg. <=2wt.% O2 and having >=2.5m<2>/g BET specific surface, and the mixed powder is calcined at 1800-2100 deg.C in a nonoxidizing atmosphere. SiO2 is substantially dissolved in AlN by the calcination, and an AlN polytype powder is obtained. Subsequently, <=2 pts.wt. of a rare-earth metal oxide powder is added as a sintering aid to 100 pts.wt. of the AlN polytype powder, the mixture is formed into a specified shape, and the formed body is sintered at 1800-2100 deg.C in a nonoxidizing atmosphere contg. N2 to obtain an AlN polytype sintered body having high-temp. strength and excellent resistance to oxidation and alkali. |
