草酸阳极氧化工艺研究

Study of Oxalic Acid Oxidation Process

针对纯草酸和草酸-硫酸混合酸两种电解液,使用不同氧化工艺制备氧化膜,观察其成膜效果。在检测膜层质量、寻找最佳工艺,并进行SEM扫描对比的基础上,分析了其性能不同的原因。结果表明:纯草酸氧化时,在浓度30~40g/L,氧化电压50V,电流密度4~5A/dm^2条件下,成膜效果最佳;膜层呈现黄偏棕色且硬度较高,耐蚀性好,但电解液稳定性较差。草酸-硫酸混合酸氧化时,电解液20~30g/L(草酸)+2.0~3.0g/L(硫酸),电压50V,电流密度4~8A/dm^2条件下,成膜效果最佳,膜层呈现古铜色,且工艺稳定。

Using two kinds of oxalic acid and oxalic acid-sulfuric acid,and different oxidation processes were used to prepare the oxide film,the film formation effect was observed.the quality of the film was tested,and the optimum process was searched,and the reason of different performance were analyzed using SEM scanning.The results showed that when the concentration of the oxalic acid was30~40g/L,the oxidation voltage was50V,the current density was4~5A/dm2,the film formation was the best,the film was yellowish brown,the hardness was relatively high,and the corrosion resistance was good,but the stability of electrolyte was relatively poor;when the concentration of the oxalic acid-sulfuric acid was20~30g/L(oxalic acid)+2.0~3.0g/L(sulfuric acid),voltage was50V,the current density was4~8A/dm2,the film formation was the best,the film was bronze,and the stability of electrolyte was relatively stable.