正脉冲电压对Mg-4Gd-3Y-0.5Zr合金微弧氧化膜组织形貌与耐蚀性能的影响

Effects of Positive Pulse Voltage on the Morphology and Corrosion Resistance of Micro-arc Oxidation Film of Rare Magnesium Alloy

摘要: 采用SEM、覆层测厚仪、电化学工作站等研究了正脉冲电压对Mg-4Gd-3Y-0.5Zr稀土镁合金双脉冲微弧氧化膜的组织形貌及耐蚀性能的影响。结果表明：随正脉冲电压的升高，膜层厚度增加，膜层表面微孔数量减少、孔径增大，烧结强度增加，裂纹增大；耐蚀性能先增强后降低，均显著优于合金基体；最佳正脉冲电压为450 V，腐蚀电位与腐蚀电流分别为-1.495 V、10-^8.62 A/cm²。

Abstract: The effects of positive pulse voltage on the morphology and corrosion resistance of micro-arc oxidation film of Mg-4Gd-3Y-0.5Zr alloy treated by double pulse micro-arc technique was investgated by SEM, coating thickness gauge and electrochemical workstation etc.The results show that fwer pores with larger diameters, more strength sintering and larger crack were found on the film when the positive pules voltage increased; Corrosion resistance of the film, which significantly better than the alloy substrate, increases first and thereafter decreases as positive pulse raise gradually; The optimal positive pulse voltage was 450 V, corrosive voltage and current were-1.495 V and 10^-8.62 A/cm².