(1. 兰州理工大学 甘肃省有色金属新材料省部共建国家重点实验室，兰州 730050；
2. 甘肃联合大学 理工学院，兰州 730000)
摘 要: 研究硅酸盐体系中AZ91D镁合金恒定小电流密度微弧氧化工艺。采用在相同工作电压下增大处理面积的原理来提高生产效率和提高微弧氧化膜层的性能。利用TT230数字式涂层测厚仪、JSM−6700F扫描电子显微镜、2206型表面粗糙度测量仪(E34−001)和W−92涂层附着力划痕实验机等研究其微观结构和CHI660C电化学工作站和UMT−2MT型球－块往复式摩擦实验机进行耐蚀性和耐磨性的评定。结果表明，此工艺稳定，可达到提高工作效率的目的，其微观结构有利于大幅度提高膜层的耐蚀性和耐磨性。
关键字: AZ91D镁合金；金属型铸造；微弧氧化；电流密度；耐蚀性；耐磨性
（1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology,Lanzhou 730050, China;
2. College of Science and Technology, Gansu Lianhe University, Lanzhou 730000, China）
Abstract:The invariable small current density process of micro-arc oxidation of magnesium alloy AZ91D were investigated in silicate electrolyte. The work efficiency was enhanced feasibly by the principle of increasing its processing area in the same operating voltage, and the properties of the micro-oxidation coating were enhanced. The microstructures were studied by means of TT230 digital coating thickness gauge, JSM−6700F scanning electron microscope (SEM), 2206 surface roughness measuring instrument (E34−001), W−92 coating adhesion scratch test machine etc, and the corrosion and wear resistance were assessed by CHI660C electrochemistry workstation and UMT−2MT ball－block reciprocating friction tester. The results show that this process is stable and can enhance the work efficiency, the microstructures are advantageous to the significant enhancement of corrosion and wear resistance.
Key words: AZ91D Mg alloy; permanent mould casting; micro-arc oxidation; current density; corrosion resistance; wear resistance
