AZ91D镁合金微弧氧化膜的制备工艺研究  

Study on Micro-arc Oxidation Processes for AZ91D Mg Alloy

作　　者：古明军[1] 林修洲[1] 杜勇[1] 李辉[1] 崔学军[1] 

机构地区：[1]四川理工学院材料腐蚀与防护四川省重点实验室,四川自贡643000

出　　处：《全面腐蚀控制》2015年第11期32-36,46,共6页Total Corrosion Control

基　　金：国家自然科学基金项目(U1333103);四川省青年科技基金项目(2014JQ0036);四川理工学院人才引进项目(2012RC06);国家级大学生创新创业训练计划项目(201310622006)资助

摘　　要：在NaAlO2电解液体系中,采用自制微弧氧化成套设备对AZ91D镁合金进行微弧氧化。采用5因素4水平正交设计试验法,以膜层厚度和耐蚀性为指标,综合考察了各因素对膜层结构和性能的影响,确定最佳工艺条件为20g/L NaAlO2,7g/L Na2B4O7,频率500Hz,正占空比20%,氧化时间30min。对该工艺下制备的微弧氧化膜层进行SEM、XRD分析,膜层含有较多的NaAlO2、MgO和Al2O3晶体相;相对基体而言,微弧氧化膜层耐蚀性提高2~3个数量级。动电位极化曲线及电化学交流阻抗测试进一步表明,AZ91D镁合金微弧氧化后,其耐蚀性明显提高。AZ91D Mg alloy was treated with micro-arc oxidation by using self-made micro-arc oxidation equipment in NaA102 electrolyte system. The orthogonal designed experiment of five factors, four levels was made to optimize best micro-arc oxidation process parameters. The thickness and corrosion resistance were examined to evaluate the influence of each factor on the structure and properties of the film, to determine the optimum conditions were 20g/L NaAlO2, 7g/LNa2B407, frequency of 500Hz, positive duty cycle 20%, oxidation time 30min. The micro-arc oxidation coating contains more MgAl2O4, MgO and Al2O3 crystals by SEM and XRD analysis. Corrosion resistance of coating was 2-3 orders magnitude higher than matrix. The result of potentiodynamic polarization curve and the electroche mical impedance spectrum show that the crrosion resistance of micro-arc oxidation coatings was improved considerably compared to AZ91D Mg alloy.

关 键 词：AZ91D镁合金 微弧氧化 正交试验 NaAlO2 耐蚀性 

分 类 号：TG174.451[金属学及工艺—金属表面处理]