| 摘要 |
PROBLEM TO BE SOLVED: To modify an Al-contg. sprayed coating excellent in corrosion resis tance and to improve its wear resistance by laminating an Ni base undercoat and an Al topcoat on the surface of a base material by a thermal spraying, executing a heating treatment and dispersedly precipitating an Ni-Al intermetallic compd. into the composite film. SOLUTION: On the surface of a base material made of metal or inorganic nonmetal, an undercoat of Ni or the alloy thereof and a topcoat of Al or the alloy thereof are laminated by a thermal spraying method, and, if required, this is laminated by >= two layers as well to form a composite film. This film may be formed by a CVD method, a PVD method, a plating method, a cementation method, a mechanical alloying method or the like. Next, the composite film is heated to a temp. equal to or above the m.p. of the metal for the topcoat. In this way, Ni and Al in the composite film are brought into alloying reaction, and hard Ni-Al intermetallic compds. such as Ni3Al, NiAl, Ni2Al3, NiAl3 and Ni2Al3 are finely precipitated to modify the structure of the soft Al-contg. film.
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