| 摘要 |
PURPOSE:To obtain an Si3N4-based ceramic molded body having superior mold releasability and post-workability by adding ammonium polyacrylate and an acrylic emulsion to a slurry of Si3N4-based ceramics and molding the slurry by casting. CONSTITUTION:A slurry (A) of Si3N4-based ceramics is composed of about 92pts.wt. Si3N4 having about 1.0mum average particle size and about 91% alpha-phase rate, about 8pts.wt. sintering assistant such as magnesia spinel having about 1.0mum average particle size and about 35pts.wt. water. Ammonium polyacrylate (B) as a deflocculant is added to the slurry A by 0.1-0.7wt.% of the amt. of the powders in the slurry A and a prescribed amt. of an acrylic emulsion (C) as a binder is further added. The slurry is then molded by casting to obtain a molded body. When the molded body is sintered at about 1,750 deg.C for about 4hr in gaseous N2 optionally after post-working, a sintered body having a desired shape is obtd. |
