单脉冲模式下电参数对镁合金微弧氧化膜耐蚀性的影响  

Effect of Electrical Parameters on Corrosion Resistance of MAO Coating Fabricated on Mg Alloy Under Unipolar Mode

作　　者：陈巧[1] 王淑艳[1] 刘莉[1] 周奉翔[1] 黄林召[1] 

机构地区：[1]江苏科技大学材料科学与工程学院,江苏镇江212003

出　　处：《热加工工艺》2013年第12期138-140,143,共4页Hot Working Technology

基　　金：江苏科技大学本科生创新计划项目(20120150);江苏高校优势学科建设工程资助项目(12504230006)

摘　　要：硅铝复合电解液体系中利用单脉冲工作模式在AZ91D镁合金表面制备了一系列微弧氧化膜层。采用四因素三水平正交实验研究单脉冲工作模式下电流密度、正占空比、氧化时间和频率对膜层耐蚀性的影响。结果表明:各电参数对膜层耐蚀性的影响程度由高到低排列依次是氧化时间、正占空比、电流密度、频率;制备较优耐蚀性膜层的电参数为:电流密度22 A/dm2,正占空比40%,氧化时间12 min,频率500 Hz;在较优工艺方案下制得的试样与镁合金相比,其自腐蚀电位提高了36.4 mV,腐蚀电流密度下降了1个数量级。Ceramic coating was obtained by micro-arc oxidation technique on AZ91D Mg alloy under unipolar mode in silicate-aluminate dual electrolyte. The effects of electrical parameters （current density, positive duty cycle, treating time and frequency） on the corrosion resistance of MAO coating fabricated on the Mg alloy were investigated by an orthogonal experiment of four factors with three levels. The results show that the order of affecting corrosion resistance from high to low is as follow： treating time, positive duty cycle, current density and frequency. Good corrosion resistance coating is obtained when the current density is 22 A/din2, positive duty cycle is 40%, treating time is 12 min and frequency is 500 Hz. Compared with the Mg alloy substrate, the corrosion potential of the coated sample increases by 36.4 mV, and the corrosion current density of the coated sample decreases one order of magnitude.

关 键 词：镁合金 微弧氧化 电参数 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]