METHOD FOR APPLYING COMPOSITE OVERLAY WELDING TO COPPER-MEMBER SURFACE

摘要

PURPOSE:To form a composite welding built-up layer which is sound and excellent in adhesive strength, by forming a metallic film combining low thermal conductivity with oxidation resistance on the surface of a copper member and by subjecting metal and ceramic powders to overlay welding onto the resulting coated surface so as to prevent the deformation of the member. CONSTITUTION:A metallic film combining low thermal conductivity with oxidation resistance is formed on the surface of a copper or copper-alloy member. As to this metallic film, it is preferable to form a Cr or Ni film to 10-200mum thickness by a plating method, etc. The above-mentioned member after film formation is preheated to about 400-500 deg.C and then overlay welding is applied to the coated surface. As the overlay welding material, a material prepared by filling a tube to be a matrix consisting of ferrous or other metals with a powder mixture to be a dispersed phase consisting of a ceramic powder of carbide, etc., and a matrix-metal powder is used. By applying a TIG welding method, etc., by using this material, a built-up layer having a composite structure consisting of a metallic matrix and a ceramic-grain dispersed phase can be formed.