抄録
Opaque oxide films from greyish white to milky white in color were obtained when Al-Mg-Si alloy sheets having been anodized at constant voltages (80 and 90V) in 2.5W/V% oxalic acid-7.5W/V% phosphoric acid mixed solution, were reanodized at constant voltages (10, 12.5 and 15V) in 15W/V% sulfuric acid solution. When the mixed acid oxide films were reanodized in sulfuric acid solution, the current of secondary anodizing recovered gradually as the reanodizing time elapsed. The cell structures of mixed acid oxide films changed as the current recovered, thus the colored opaque oxide films were obtained.
