恒压恒流交互模式对AZ31B镁合金微弧氧化陶瓷膜组织与性能的影响  

Effect of Constant Voltage and Constant Current Interaction Mode on Microstructure and Properties of Micro-Arc Oxidation Ceramic Film on AZ31B Magnesium Alloy

作　　者：束银凤 姜波 王超 宋仁国[1,2] SHU Yinfeng;JIANG Bo;WANG Chao;SONG Renguo(School of Materials Science and Engineering,Changzhou University,Changzhou 213164,China;JiangsuKey Laboratory of Materials Surface Science and Technology,Changzhou University,Changzhou 213164,China)

机构地区：[1]常州大学材料科学与工程学院,江苏常州213164 [2]常州大学江苏省材料表面科学与技术重点实验室,江苏常州213164

出　　处：《材料保护》2024年第2期35-42,共8页Materials Protection

基　　金：国家自然科学基金资助项目(51871031)。

摘　　要：为探究恒压与恒流相互叠加模式对AZ31B镁合金微弧氧化膜层组织与性能的影响,利用AZ31B镁合金为基材,在电解液和电参数相同的前提下,采用恒流、恒压、先恒流再恒压、先恒压再恒流4种不同电源工作模式在AZ31B镁合金表面制备微弧氧化陶瓷膜。采用扫描电镜(SEM)、电化学工作站、X射线衍射仪(XRD)、高温摩擦磨损机等检测手段,对AZ31B镁合金微弧氧化陶瓷膜层进行测试。结果表明:基材经微弧氧化处理后,表面生成微弧氧化陶瓷膜。在先恒流再恒压(0.7 A/6 min+400 V/4 min)电源模式下制备的微弧氧化陶瓷膜的MgO、MgF_(2)以及Mg_(2)SiO_(4)等强化相的峰值比其他模式下制备的膜层高;膜层表面平整,微孔小且分布均匀,致密性较好,膜层与基体紧密结合;相对于其他模式下的膜层,其被磨穿时长最长,材料的耐磨性得到提升;其腐蚀电位相对于基体,从-1.4974 V增加到-1.3769 V,腐蚀速率从0.0091 mm/a降低到0.0020 mm/a,耐腐蚀性显著提升。In order to study the effect of the superposition mode of constant voltage and constant current on the microstructure and properties of micro-arc oxidation coatings on AZ31B magnesium alloy,the AZ31B magnesium alloy was used as substrate under the condition of the same elec-trolyte and electric parameters,and micro-arc oxidation(MAO)ceramic coatings were prepared on AZ31B magnesium alloy by four different pow-er supply working modes:constant current,constant voltage,first constant current and then constant voltage,first constant voltage and then con-stant current.Subsequently,scanning electron microscopy(SEM),electrochemical workstation,X-ray diffraction(XRD)and high-temperature friction and wear tester were used to characterize the MAO ceramic coatings on AZ31B magnesium alloy.Results showed that after the substrate was treated with micro-arc oxidation,a micro-arc oxidation ceramic coating was formed on the surface.The peaks of MgO,MgF_(2) and Mg_(2)SiO_(4) reinforcement phases of the as-prepared MAO coating under the power mode of first constant current and then constant voltage(0.7 A/6 min+400 V/4 min)were higher than those under the other modes.In addition,the surface of MAO ceramic coatings was flat,the micropores were small and evenly distributed,the compactness was good,and the coatings was closely combined with the substrate.Compared with the coatings obtained under the other modes,the wear time of the coating prepared under the power mode of first constant current and then constant voltage had the longest wear through time,and the wear resistance of the material was improved.In the comparison of the substrate,the corrosion po-tential of the coating prepared under the power mode of first constant current and then constant voltage increased from-1.4974 V to-1.3769 V,and the corrosion rate was reduced from 0.0091 mm/a to 0.0020 mm/a,indicating that the corrosion resistance was significantly improved.

关 键 词：AZ31B 镁合金 恒压恒流交互 微弧氧化 组织 性能 

分 类 号：TG174[金属学及工艺—金属表面处理]