| 摘要 |
PROBLEM TO BE SOLVED: To impart strong antibacterial property, algicidal property mildewproofness and excellent durability to a metallic material by coating the surface of a base metal such as Al, stainless steel and Ti with an Ni-P alloy film having specified contents of P, H, S and Cl. SOLUTION: The surface of a base metal is coated with an Ni-P alloy film contg. 2-5 mass % P and further, as required, 0.00001-0.005% H, 0.0025-0.1% S and 0.001-0.01% Cl. The elution of Ni is preferably controlled to 1-50 μg/cm<2> / week when dipped in still water at 30 deg.C, the surface roughness to >=0.25 μm central line mean roughness Ra, the surface hardness to 500 Hv and the minimum film crazing load to >=10 kgf /cm<2> in Vickers indentation test. The Ni-P alloy film is formed by electroplating, etc., and the film thickness is controlled to >=15 μm when formed especially on a metallic substrate of Al, etc., baser than the alloy film. |
