电流模式对镁合金微弧氧化膜性能的影响

Effects of Current Mode on Properties of Anodic Coatings of Magnesium Alloys

摘要:

采用Tagnite工艺，研究了3种电流控制方式：恒流、单脉种（正脉冲）以及双脉冲（正、负脉冲）对AZ91HP镁合金氧化膜性能的影响。3种控制方式制得的氧化膜，表面均匀结构致密，双脉冲时单位面积孔的数量最少，恒流和单脉冲没有明显的区别。对比3种氧化膜孔的均匀性，双脉冲最均匀，恒流最差。利用EDS对氧化膜成分进行分析，氧化膜中均含有硅、氧、镁和氟等。盐雾实验表明，双脉冲方式得到的氧化膜耐蚀性最好，恒流方式最差。

Abstract:

Adopting process of tagnite, effects of three current controlling, modes, namely constant current, unipolar current and bipolar current on properties of anodic coatings of AZ91HP magnesium alloys were studied, coatings formed by the three methods were all compact, the number of pores per unit by bipolar current was the least among them , and there was no difference between those by constant current and unipolar current. The uniformity of pore size for the coating obtained by bipolar current was the best and that by constant current was the worst. According to EDS analysis, these coatings contained Si, O, Mg and F. Salt spray test showed that corrosion resistance of the coating by bipolar current was the best and the coating by constant current the worst.