| 摘要 |
PURPOSE:To improve strength by forming microcrystals of Y2Hf2O7, crystals of Yalpha-sialon having a specified compsn., crystals of beta-sialon and a Y-contg. glass phase is constituents. CONSTITUTION:Powdery starting material consisting of <=50wt.% Yalpha-sialon powder contg. 8wt.% excess of O2 over the theoretical amt. of O2 defined by Yalpha-sialon represented by formula I (where 0<x<=2), <=15wt.% HfO2 powder and the balance alpha-Si3N4 powder is mixed and sintered by heating at 1,600-2,100 deg.C in an N2 atmosphere to obtain a high strength sialon-based sintered body consisting of 1-20wt.% microcrystal phase of Y2Hf2O7, 5-50wt.% crystal phase of Yalpha-sialon, 30-90wt.% crystal phase of p-sialon represented by formula II (where 0<z<=4.2) and 1-10wt.% Y-contg. glass phase. |
