ALUMINUM ALLOY HAVING EXCELLENT ANODIC OXIDATION TREATABILITY, AND ANODIC-OXIDATION-TREATED ALUMINUM ALLOY MEMBER

摘要

An aluminum alloy comprising more than 3.5% and up to 6.0% of Mg, 0.02 to 1.0% inclusive of Cu, 0.02 to 0.1% inclusive of Cr, and a remainder made up by Al and unavoidable impurities, wherein the contents of Si and Fe in the unavoidable impurities are limited to 0.05% or less and 0.05% or less, respectively, and wherein the number of intermetallic compound particles contained in the aluminum alloy and having a maximum length of 4 mum or more is 50 particles or less per 1 mm2 of an arbitrary cross-sectional area of the aluminum alloy. An aluminum alloy is provided, which has excellent anodic-oxidation-treatability and can be used for providing an anodic-oxidation-treated aluminum alloy member having high withstand voltage properties and such excellent heat resistance that the occurrence of cracking under high temperatures conditions can be prevented.