SURFACE TREATING METHOD FOR ALUMINUM PRODUCT

PROBLEM TO BE SOLVED: To obtain a smooth surface and to satisfactorily apply it particularly to a sliding member by applying a roller on the surface of an Al or Al alloy material subjected to anodizing treatment and crushing projections of the surface. SOLUTION: The application of a roller on an Al material subjected to anodizing treatment can be executed by using a roller leveller executing the improvement of the surface properties of the working face in the stock after machining and rolling. As a result, the surface roughness can remarkably be improved, and it is made smooth. Then, the side of the projecting parts (projections) in the ruggedness of the anodized layer is crushed by a ratio higher than that in the side of the recessed parts, and the recessed parts are relatively largely left. In this way, the recessed parts function as oil reservoirs in the sliding face, and it is made suitable for the sliding member. At this time, the thickness of the anodized layer by the application of the roller does not nearly change, and it is about 0.5 to 1.0 μm at the maximum. Moreover, by the application of the roller, the hardness of the surface of the anodized layer increases, and its wear resistance improves also by this increase.