硫酸镧对汽车用铝合金阳极氧化膜性能的影响

在汽车用2024铝合金阳极氧化使用的电解液中添加硫酸镧,并研究了硫酸镧的质量浓度对阳极氧化膜的厚度、膜重、硬度、表面形貌及耐蚀性的影响。结果表明:硫酸镧的催化作用有利于提高氧化速率,减小多孔层的孔径,从而提高阳极氧化膜的硬度及耐蚀性。当硫酸镧的质量浓度为0.8 g/L时,阳极氧化膜具有最高的硬度和最佳的耐蚀性。但当硫酸镧的质量浓度大于0.8 g/L时,稀土的吸附作用会使阳极氧化膜的性能有所降低。

Effect of Lanthanum Sulfate on Properties of Anodic Oxide Film on Surface of Aluminum Alloy for Automobile

Lanthanum sulfate was added into the electrolyte used for anodizing of 2024 aluminum alloy for automobile,and the effect of mass concentration of lanthanum sulfate on the thickness,weight,hardness,surface morphology and corrosion resistance of the anodic oxide film was studied.The results showed that the catalytic effect of lanthanum sulfate was beneficial to improve the oxidation rate and refine the pore diameter of porous layer resulting in the improvement of hardness and corrosion resistance of anodic oxide film.The anodic oxide film prepared under the condition of 0.8 g/L lanthanum sulfate possessed the highest hardness and best corrosion resistance・When the mass concentration of lanthanum sulfate was higher than 0.8 g/L,the properties of the anodic oxide film was decreased due to the adsorption capacity of rare earth.