ALUMINUM ALLOYS FOR FORMING COLORED ANODIC OXIDE FILMS THEREON AND METHOD FOR PRODUCING A SHEET MATERIAL OF THE ALLOY

摘要

ALUMINUM ALLOY FOR FORMING COLORED ANODIC OXIDE FILMS THEREON AND METHOD FOR PRODUCING A SHEET MATERIAL OF THE ALLOY An aluminum alloy consists of, by weight, from 0.08 to 0.50 percent silicon, from 0.15 to 0.90 percent iron, the weight ratio of iron to silicon being from 1.4 to 2.2, and the remainder aluminum, intermetallic compounds of .alpha.-type Al-Fe-Si system being contained in the alloy. A light gray oxide film is formed on the alloy by anodic treatment.