Preparation of the Preform of Pure Carbon Reaction Bonded Silicon Carbide by In-situ Consolidation Molding Method

摘要

A new kind of in- situ ceramic consolidation molding process was investigated on the basis of the characteristics of starch swelling in water and gelatinizing when heated. The SiC ceramic suspension containing about 50vol percent solids loading and about 3wt percent starch can be cast and molded into various complex-shape SiC ceramic parts in a water-thermostat. The dry shrinkage of the green body was less than 1.0 percent when the solid volume fraction of SiC suspension was up to 52.5 percent. The density and pore size were homogeneously distributed inside the biscuits. Soaked with melt silicon in a vacuum arc furnace, the biscuits were turn into SiC ceramic materials with homogeneous structure and high performances.