BINDER FOR INJECTION MOLDING OF CERAMIC AND PRODUCTION OF SINTERED CERAMIC USING THE SAME

摘要

PURPOSE:To suppress the generation of microcracks by mixing ceramic with an organic binder composed of paraffins containing specific carbon number components at specific ratios, injection-molding the obtained molding raw material and baking the molded article after degreasing. CONSTITUTION:An organic binder composed mainly of 18-35C paraffins is mixed with powdery ceramic such as Si3N4 at a volume ratio of 40/60 to 55/45 to obtain a ceramic material for injection molding. The paraffin used as the main component of the organic binder contains 22-27C component at the highest ratios. The content of 31C component is larger than that of 30C component and the content of 33C component is larger than that of 32C component. The ceramic raw material is injection-molded and the temperature is raised to 400-600 deg.C spending 2-15hr to effect the degreasing of the product and obtain a degreased molded article free from microcracks. The degreased molded article is baked in N2 atmosphere at 1550-1800 deg.C under normal pressure and at 1700-2000 deg.C under pressure in the case of sintered Si3N4 or baked in Ar atmosphere at 1900-2200 deg.C under normal pressure in the case of sintered SiC.