FORMATION OF HARD ANODIC OXIDE FILM AND ALUMINUM ALLOY FOR FORMING THE FILM

摘要

PURPOSE: To form a high-hardness anodic oxide film uniform in the thickness direction on an aluminum alloy by using an ordinary-temp. electrolytic bath. ;CONSTITUTION: An aluminum alloy, e.g. Al-Mn, Al-Mn-Mg alloy, etc., in which an intermetallic compd. deposit insoluble or sparingly soluble in sulfuric acid and having 0.01-3μm particle diameter is dispersed at a density of ≥1×10⁴ units/mm² and is used as a substrate 1. The surface of the substrate 1 is anodized by a sulfuric-acid electrolytic bath kept at 12-30°C to form a hard anodic oxide film 2 having ≥350Hv hardness.;COPYRIGHT: (C)1994,JPO