Plating method for aluminum alloy material
There is provided a method of applying plating to an aluminum alloy material, which comprises a step of cathodic acid electrolysis as a pretreatment for the plating for removing insoluble matters from the aluminum alloy generated in a previous alkaline-etching step.
1 . A method of applying plating to an aluminum alloy material, which comprises a step of cathodic acid electrolysis as a pretreatment for the plating for removing insoluble matters in the aluminum alloy generated in a previous alkaline-etching step.
2 . The method according to claim 1 , wherein the cathodic acid electrolysis is performed in a solution of ferric sulfate with the aluminum alloy material being employed as a cathode.
3 . The method according to claim 1 , wherein the aluminum alloy material is a cylinder for an internal combustion engine wherein the plating is applied to a sliding surface of piston of the cylinder.
4 . The method of claim 3 wherein the iron plating is applied to the sliding surface of the piston.
5 . A cylinder for an internal combustion engine, which is featured in that a sliding surface of piston thereof is applied with an iron plating according to the method claimed in claim 3 .
6 . A method of applying plating to an aluminum alloy material, which comprises the steps of:
degreasing the aluminum alloy material;
subjecting the degreased aluminum alloy material to an alkali-etching treatment;
subjecting the alkali-etched aluminum alloy material to cathodic acid electrolysis;
subjecting the electrolyzed aluminum alloy material to an anodic oxidation treatment; and
applying plating to the anodically oxidized aluminum alloy material.
7 . The method according to claim 6 , wherein the cathodic acid electrolysis is performed in a solution of ferric sulfate with the aluminum alloy material being employed as a cathode.
8 . The method according to claim 6 , wherein the aluminum alloy material is a cylinder for an internal combustion engine wherein the plating is applied to a sliding surface of a piston of the cylinder.
9 . The method of claim 8 wherein the iron plating is applied to the sliding surface of the piston.
10 . A cylinder for an internal combustion engine, which is featured in that a sliding surface of piston thereof is applied with an iron plating according to the method claimed in claim 8.