ADC12アルミニウムダイカスト合金の硫酸溶液中における多孔質アノード酸化皮膜の生成挙動に及ぼす加熱処理の影響
1991 年 42 巻 9 号 p. 933-940
詳細
1991 年 42 巻 9 号 p. 933-940
ADC12 aluminum die casting alloy was heat-treated for various periods, th' at different temperatures, Th' and anodized in 10wt% sulfuric acid solution at 20°C by applying a constant current density, ia' of 100A/m2. The film formation behavior and film properties were examined as functions of Th' th and the abrasion thickness, X, of specimens by scanning electron microscopy (SEM), chemical analysis, and diffuse reflectance spectroscopy (DRS).
The steady value of anode potential, Ea*, was found to decrease with increasing Th' th' and X. The ratio of dissolution current to ia decreased with Th and th, and was independent of X. Oxide films formed after anodizing for 40min showed thickness differences on all specimens, and the variation in film thickness decreased with increasing Th' th' and X. The value of average film thickness, δ, increased with Th' th' and X and this is expected to be due to an contribution of oxygen gas evolutions. DRS showed that the degree of film coloration decreases with increasing Th' th and X.
The film formation mechanism is discussed with reference to structural change in the metal substrate due to heat treatment.
