| 摘要 |
PURPOSE:To obtain in high reproducibility to any shape a fiber-containing silicon nitride baked form imparted with uniform electrical resistance and high thermal shock resistance by incorporating silicon nitride powder with specific electrically conductive inorganic fibers. CONSTITUTION:A water-based slurry of silicon nitride is first prepared by incorporating (A) 100 pts.wt. of silicon nitride powder 0.2-3.0mum in mean particle diameter with (B) 40-80 pts.wt. of water and, where appropriate, (C) 0.3-1.5 pts.wt. of an inorganic sintering auxiliary such as alumina or yttrium oxide and (D) 0.2-2.0 pts.wt. of a dispersant such as a polycarboxylic acid. Next, 1..-50vo1.%, based on the silicon nitride powder, of electrically conductive inorganic fibers such as carbon fibers or silicon carbide fibers 0.05 l 5.00 mm in mean length, 1 l 20 p m in mean section diameter and 5 l 100 in aspect ratio are homogeneously dispersed in this slurry, and the resultant slurry is cast in a desired gypsum mold to obtain a slip cast molded form. This molded form is then dried in air at 20-60 deg.C and subjected to HIP or hot press baking treatment in a nonoxidative atmosphere such as N2 or Ar gas at 1600 [ 800'C under a pressure of 100-2000kg/cm<2>. |
