Patent ID: 9005765
Filing Date: 2015-04-14
Classification: C25D

Abstract:
1. A method for forming an anodic oxide film, the method comprising: anodizing a surface of a Japanese Industrial Standards (JIS) 6061 aluminum alloy substrate in a solution of sulfuric acid or in a solution of an acid mixture of sulfuric acid and oxalic acid to form the anodic oxide film thereon, wherein the anodic oxide film has a crack density of 1 mm/mm the anodizing is performed at an integrated voltage in a film thickness direction over the thickness of the anodic oxide film formed of 1650 V·μm or more, the anodizing is performed at a bath voltage of 27 V or less to form the anodic oxide film in a region from a position 25 μm, in the film thickness direction, above from an interface between the aluminum alloy substrate and the anodic oxide film to a surface of the anodic oxide film, and the anodizing is performed at an integrated voltage of 820 V·μm or more and 1000 V·μm or less to form the anodic oxide film in a region from the interface to the position 25 μm, in the film thickness direction, above from the interface.