| 摘要 |
PROBLEM TO BE SOLVED: To obtain a thermal spray coating film having excellent corrosion resistance without sealing treatment by forming a base layer of an Al-Ni alloy thermal spraying film and then forming a ceramic thermal spraying film. SOLUTION: A base layer 1 formed on the surface of a base material 3 such as an aluminum alloy and iron alloy consists of a thermal spray layer of 100 to 200μm thickness comprising 5 to 20wt.% Al and the balance Ni. Then a ceramic thermal spray layer 2 of >=150μm thickness is formed thereon. By forming the base layer 1 essentially comprising Ni, excellent adhesion property for thermal spraying to the base body 3 can be obtd., and the base layer 1 has a medium coefft. of thermal expansion between the upper ceramic layer 2 and the base body 3 so that the corrosion resistance and the preventing effect against peeling due to residual stress in the ceramic layer 2 can be maintained. Moreover, since the base layer contains Al, the melting point is lowered to reduce the porosity when the coating film is formed. Further, when the obtd. material is used in a corrosive environment, pores are sealed by expansion of the volume accompanying the production of Al oxides to improve the corrosion resistance. |
