COPPER ALLOY FOR MOLD MATERIAL FOR MOLDING PLASTICS

PURPOSE:To obtain the copper alloy combining excellent heat conductivity and high temp. strength and having small lowering of toughness at a high temp. by specifying the compsn. constituted of Ni, Si, Zn, Mg, Cr, Ti, Zr and Cu. CONSTITUTION:The copper alloy for a mold material for molding plastics contains, by weight, 0.4 to 4.0% Ni, 0.1 to 1.0% Si, 0.05 to 1.0% Zn and >0.01 to 0.5% Mg, contains 0.001 to 0.01% of at least one kind among Cr, Ti and Zr and the balance Cu with inevitable impurities. The alloy combines excellent high temp. strength and heat conductivity and in which molding time can be shortened. In the above alloy, the lowering of toughness at a high temp. is furthermore small and the brittle crack of a mold at the time of hot working can be prevented.