Patent ID: 8691403
Filing Date: 2014-04-08
Classification: C25D

Abstract:
1. An anodized aluminum film on an object made of an aluminum alloy, which has been formed by anodizing the object in an electrolytic solution containing one acid selected from organic acids with two or more carboxylic groups, and 0.005% to 0.01% by weight of sulfuric acid under conditions that the electrolytic solution moves at least at an outer surface side of the object at an average speed of not more than 15 cm/sec, and an outer surface temperature of the object is not more than 80° C., and the current density is in the range of 10 to 170 A/dm 2 , wherein the anodized aluminum film is 0.5 to 5 μm in thickness, not more than 2.4 μm in surface roughness, and not less than 250 Hv in Vickers hardness; and said aluminum alloy comprising aluminum of 80.7 to 88.9% by weight and silica of 9.6 to 12.0% by weight.