Method for production of metal material

Abstract

A method for producing a metal material involves applying, to the surface of the ZAS alloy, an agent comprising a solvent and, dispersed therein, a material containing Cu such as Cu powder and a Cu—Mn alloy powder and preferably, dispersed or dissolved therein, a reducing agent capable of reducing an oxide film present on the surface of the ZAS alloy, and heating the ZAS alloy having the agent applied thereon, to thereby diffuse Cu into the alloy. The metal material comprises a Zn—Al—Sn based alloy (ZAS alloy) and Cu diffused in the alloy, wherein Cu is diffused into the inside of the alloy to a depth from the surface of 0.5 mm or more, the concentration of Cu decreases from the surface of the ZAS alloy towards the inside thereof, and there is present no specific interface between Cu and the ZAS alloy.

1 . A method of producing a metal material comprising a diffusion layer which is formed by diffusing an element into a base material of a metal and which has a depth from a surface of said base material of not less than 0.5 mm, a concentration of said element being gradually decreased from said surface to inside of said base material, said method comprising:
 adding at least one of copper and manganese as a seeding agent to a molten metal when casting is performed by using said molten metal of Zn or a Zn alloy.   
   
   
       2 . The method of producing said metal material according to  claim 1 , wherein said casting is started 10 to 30 seconds after said seeding agent is added to said molten metal. 
   
   
       3 . The method of producing said metal material according to  claim 1 , wherein said at least one of copper and manganese is an added powder having a particle size of 10 μm to 50 μm. 
   
   
       4 . The method of producing said metal material according to  claim 2 , wherein said at least one of copper and manganese is an added powder having a particle size of 10 μm to 50 μm. 
   
   
       5 . The method of producing said metal material according to  claim 1 , wherein copper is added as the seeding agent, and said copper is seeded in an amount of 1% by weight to 18% by weight of an entire amount of said Zn or said Zn alloy. 
   
   
       6 . The method of producing said metal material according to  claim 1 , wherein manganese is added as the seeding agent, and said manganese is seeded in an amount of 3% by weight to 30% by weight of said seeding agent.