氨基酸类有机添加剂对镁合金阳极氧化的影响及其作用机制研究

The effect and mechanism of amion acid on the anodic oxidation of magnesium alloy

摘要:

为了进一步改善镁合金表面阳极氧化膜的质量和性能，在NaOH Na2SiO3基础电解液中添加氨基酸类有机添加剂对AZ31镁合金进行阳极氧化，研究了氨基酸类有机添加剂对镁合金阳极氧化过程及氧化膜厚度、表面形貌、结构及耐蚀性的影响。探讨了有机添加剂在镁合金阳极氧化中的作用机制。结果表明：不同的氨基酸对镁合金阳极氧化过程及氧化膜性能影响不尽相同，其中乙二胺四乙酸和L-鸟氨酸醋酸盐可显著提高阳极氧化的击穿电压，起到明显的抑弧作用，大幅度提高了氧化膜的厚度、致密性和耐蚀性能。有机添加剂主要通过缓蚀、抑弧和表面活性剂三方面的综合作用来影响镁合金阳极氧化的过程及氧化膜的性能。

Abstract:

To further improve the quality and performance of oxidation film，AZ31 magnesium alloy were anodized in NaOH Na2SiO3 base electrolyte with different aminoacetic acid as organic additives. The effects of different amino acids on the thickness, morphology, structure and corrosion resistance of anodizing films were investigated. The mechanisms of organic amino acids additives were discussed. Results show that there are different effects on the anodizing of magnesium alloy after adding different amino acids in electrolyte. EDTA and L-Orn have remarkable effect on arc restraining, which resulted in an increase in the thickness of anodizing films and a decrease in the surface micro-hole size and porosity, and finally the improvement in corrosion resistance. Organic additives, mainly through the combined effect of inhibition, arc suppression, and surfactant, affect the anodizing process and the performance of oxide film.