| 摘要 |
PURPOSE:To obtain the title sintered form improved in density and mechanical strength, by grinding, using a specific grinder, a mixture comprising silica- reduced Si3N4 powder and a sintering aid, followed by spiking with a binder and granulation, forming and then calcination. CONSTITUTION:Firstly, 100pts.wt. of silica-reduced Si3N4 powder 0.4-1.5wt.% in carbon content, >=90% in alpha-conversion rate and 1-5mum in average particle size is incorporated with 0.3-30pts.wt. of a sintering aid 0.2-2mum in average particle size comprising (A) 0.1-10pts.wt. of yttria >=99.0% in purity and <=8.0mum in maximum particle size, (B) 0.1-10pts.wt. of alumina >=99.5% in purity and <=5.0mum in maximum particle size, and (C) 0.1-10pts.wt. of AlN >=98.5% in purity and <=6.0mum in maximum particle size followed by grinding, using a grinder lined and/or with its ball consisting of alumina or Si3N4 to prepare mixed powder 0.5-1.5mum in average particle size containing 0.3-3wt.% of alumina or Si3N4. Thence, this mixed powder is spiked with a binder followed by granulation and forming to eliminate said binder followed by calcination. |
