| 摘要 |
PURPOSE:To improve heat resistance and thermal impact resistance by using mullite type powder having a specific average grain size and contg. SiO2 and Al2O3 at high ratios as aluminosilicate powder. CONSTITUTION:The aluminosilicate powder consisting of the mullite type powder having <=5mum average grain size and contg. >=99.5wt.% SiO2 and Al2O3 and carbon powder are respectively weighted at prescribed ratios and mixed. Further, beta-sialon or >=1 kinds of the oxides of the rare earths selected from Y, Ce, La, and Hf are compounded at 0.03 to 0.3 pts.wt per 1 pt.wt. aluminasilicate powder. This powder mixture is then brought into reduction reaction by heating for 0.5 to 6 hours at 1350 to 1600 deg.C in an N2-contg. atmosphere, by which the high-purity beta-sialon powder expressed by formula (0<Z<=4.2) is obtd. |
