Study on the Gel Casting Process of Silicon Carbide

Abstract

Silicon carbide possess high performances such as high hardness and strength, oxidation and high temperature resistance, high thermal conductivity and low thermal expansion coefficient. Widely used methods of molding green body for sintered pressureless bonded silicon carbide comprise dry pressing molding and casting molding. The former fails in preparation of complex shapes, while those prepared by casting molding are prone to have defects such as nonuniformity of density and easy cracking. Gel-casting is a net-shape modeling technology caused by the polymerization of organic monomer (acrylamide). The green bodies molded by gel-casting have uniform structure, high density, high strength and machinability. In this study, gel casting molding and pressureless sintering were used to prepare silicon carbide. The effect of the parameters of gel casting and sintering on the microstructure of the obtained silicon carbide was examined