| 摘要 |
PURPOSE:To enhance the surface strength and the surface corrosion resistance of a die cast product, by a method wherein the surface of the die cast product comprising a soft metal inferior to corrosion resistance is coated with an other metal and the coated metal is diffused by heating under a specific temp. CONSTITUTION:A die cast product based on Zn or Al, Sn or Sb is subjected to surface treatment to enhance the hardness and corrosion resistance of the surface thereof. In order to obtain these effects, Cu plating is applied to the surface of the cast product as primer plating while Ni plating is further applied thereto and Au, Ag, Rh or ther metal excellent in heat diffusibility is applied as a top decorative finishing layer. This coated cast product is heated to a temp. within a range from about 150 deg.C to about melting tamp. of the metal constituting the die cast product to generate diffusion due to heat treatment between mutual metals and an alloy layer excellent in hardness and corrosion resistance is formed. |
