基于激光冲击的镁合金在NaCl溶液中电化学腐蚀的研究  

Study on Electrochemical Corrosion of Magnesium Alloys by Laser Shock Processingin NaCl Solution

作　　者：张青来[1] 钱阳[1] 安志斌[2] 李兴成[1] 张永康[3] 王思顺[1] 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013 [2]空军工程大学工程学院,陕西西安710038 [3]东南大学机械工程学院,江苏南京210096

出　　处：《中国激光》2014年第9期76-82,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(51175231)

摘　　要：为了研究激光冲击强化对镁合金耐腐蚀性的影响,采用电化学方法和钕玻璃脉冲激光(波长1064nm,脉冲宽度20ns)研究AZ31、AZ61和AZ91三种镁合金在3.5%(质量分数)NaCl溶液中的电化学腐蚀行为,并对合金表面形貌、微观组织、显微硬度、自腐蚀电位和电化学阻抗谱进行实验测试与分析。结果表明:激光冲击强化改善了镁合金的耐腐蚀性。随着激光功率密度的增加镁合金自腐蚀电位正向移动,腐蚀电流密度降低,阻抗弧变大。当功率密度为0.7GW/cm2时电流密度开始增加,阻抗弧减小。讨论和分析了Al含量、固溶和时效处理对激光冲击镁合金自腐蚀电位和阻抗谱的影响。In order to study the effect of laser shock processing（LSP）on the electrochemical corrosion resistance of magnesium alloys,the electrochemical corrosion behaviors in 3.5%（mass fraction）NaCl solution of AZ31,AZ61 and AZ91 magnesium alloys are investigated by electrochemical method and Nd：glass laser with the wavelength of 1064 nm and pulse width of 20 ns.Its surface morphologies,microstructures,microhardness,self-corrosion potential and electrochemical impedance spectroscopy（EIS）are also examined and analyzed.The experimental results show that electrochemical corrosion resistance of magnesium alloys are improved after LSP.With the increasing of laser power density,the self-corrosion potential of magnesium alloy begins to move towards a positive direction,the corrosion current density decreases and the impedance arc becomes larger.When power density reaches to 0.7 GW/cm2,the current density increases and impedance arc becomes smaller.The effect of the Al content,solution and aging treatment on the corrosion potential and EIS of magnesium alloys by LSP are discussed and analyzed.

关 键 词：激光光学 镁合金 激光冲击强化 自腐蚀电位 电化学阻抗谱 微观组织 

分 类 号：TN249[电子电信—物理电子学] TG146.22[一般工业技术—材料科学与工程]