| 摘要 |
PURPOSE:To enlarge Si3N4 grains and to obtain a silicon nitride body having high heat conductivity by pulverizing and mixing starting material for silicon nitride contg. a limited amt. of Al using of ball stones made of silicon nitride, molding and firing the mixture. CONSTITUTION:Starting material for silicon nitride contg. <=0.3wt.% (expressed in terms of Al2O3) Al is pulverized and mixed using of ball stones made of silicon nitride so as to prevent impurities from entering the starting material and then the resulting mixture is molded and fired. A silicon nitride body having <=20 Si3N4 grain boundaries per 10mum length of a straight line drawn on an arbitrary cross section is obtd. This silicon nitride body contains Si3N4 as beta-Si3N4 and has >=0.15Cal/cm.sec. deg.C heat conductivity. |
