BONDING AGENT FOR POWDER INJECTION MOLDING AND POWDER INJECTION MOLDING PROCESS USING THE SAME

摘要

PURPOSE: A bonding agent for powder injection molding and powder injection molding process using the same are provided, which can prevent thermal deformation due to pyrolysis of polymer during sintering. CONSTITUTION: The bonding agent for powder injection molding comprises (a) 60 to 95 wt.% of paraffin wax and polybutyl methacrylate and (b) a balance of ethylenevinylacetate, wherein paraffin wax and polybutyl methacrylate is included in the binding agent at a ratio of 90:10 to 10:90. The powder injection molding process using the same includes the steps of (a) preparing an injection-moldable pellet by mixing the binding agent with metal or ceramic powder, wherein the metal is one or more than two elements selected from iron, iron-nickel and stainless, and the ceramic is one selected from oxides, nitrides, carbide, cermet; (b) injection-molding the pellet; (c) extracting paraffin wax and polybutyl methacrylate out of the injection-molded material with petroleum solvent at less than 60 deg.C; (d) removing ethylene vinyl acetate by pyrolysis; and (e) sintering the injection-molded material after removing binding agent.