| 摘要 |
PURPOSE:To homogenize a sintered compact without deteriorating the mechanical strength and to stably obtain a high strength sintered compact with no unevenness in characteristics. CONSTITUTION:A silicon nitride sintered compact consisting of a silicon nitride crystal phase and a glass phase and/or a crystal phase contg. at least a group IIIa element of the periodic table as a grain boundary phase is heat-treated in a nonoxidizing atmosphere contg. tungsten oxide or silicon oxide at. 1,050-1,290 deg.C. |
