| 摘要 |
PURPOSE:To obtain ceramics which has excellent resistance to a molten metal while maintaining a high temp. characteristic by coating an Mg compd. soln. on the surface of a sintered body of silicon-contg. non-oxide ceramics and subjecting the coating to a heat treatment after drying. CONSTITUTION:The magnesium compd. soln. is coated on the surface of the sintered body of the silicon-contg. non-oxide ceramics. The coating is subjected to the heating treatment after drying, by which the oxide surface layer essentially consisting of magnesia is formed. The silicon-contg. non-oxide ceramics include silicon nitride, sialon, silicon carbide, etc. The sintered bodies of the silicon nitride and sialon have high strength and excellent thermal impact resistance. Sintering of the silicon nitride can be executed by an atm. pressure sintering method, pressure sintering method, gaseous pressure sintering method, etc., and the sintering temp. is about 1,650-1,800 deg.C. The reactivity of the magnesia, iron oxide and copper oxide in the resultant ceramics is extremely low (the bascisity is extremely approximate). The ceramics is, therefore, not eroded by molten iron and copper in spite of contact therewith in an oxidatizing atmosphere.
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