| 摘要 |
PURPOSE:To obtain ceramic Si3N4 having excellent heat resistance, thermal shock resistance, strength in a wide temperature range and high uniformity, by adding a specific additives to Si3N4 and sintering. CONSTITUTION:100pts.wt. Si3N4 having >=90% ratio of crystallization of alphatype and <=1mum average particle diameter is blended with 3.0-15.0pts.wt. Y2O3 and/or R2O3 (R is rare earth element of La type), 3.0-10.0pts.wt. MgAl2O4, 0.1-1.0pt.wt. Cr2O3 and 0.1-1.0pt.wt. SiO2 as additives, dried and ground to give dried powder having 30-120mum average particle diameter. Then the dried powder is press molded by a mold and sintered under heating at normal pressure in an N2 gas atmosphere at 1,600-1,800 deg.C for 30min-sevral hours. |
