AM50镁合金表面激光喷丸强化层耐蚀性能与机理研究  

Research on Corrosion Resistance and Mechanism of Strengthened Layer on AM50 Mg Alloy Surface Processed by Laser Shot Peening

作　　者：陈菊芳[1,2] 李兴成[1,2] 周金宇[1] 叶霞[1] 

机构地区：[1]江苏技术师范学院材料工程学院,江苏常州213001 [2]江苏大学光子制造科学与技术重点实验室,江苏镇江212013

出　　处：《中国激光》2011年第12期53-58,共6页Chinese Journal of Lasers

基　　金：国家自然科学基金(50805070);江苏省科技计划项目(BK2011261);江苏省高校自然科学基金(09KJB460002)资助课题

摘　　要：为了研究激光喷丸强化对镁合金耐蚀性能的影响,采用钕玻璃激光对AM50镁合金表面进行喷丸强化实验。结果表明,当激光功率密度约3GW/cm2时,表层材料发生塑性变形,致密度、硬度提高并产生较大的残余压应力,表面残余压应力高达146MPa。电化学极化曲线测试结果显示,激光喷丸表面的自腐蚀电位和点蚀电位较未处理试样分别提高了64mV和92mV,腐蚀电流密度降低了88.6%。在盐雾环境下连续喷雾20h后,未处理试样表面较激光喷丸试样表面出现了更多更大的点蚀坑,激光喷丸后镁合金表面的腐蚀面积减小了84.7%。激光喷丸强化使镁合金表面的耐蚀性能得到了显著提高。In order to study the influence of laser shot peening （LSP） on the corrosion resistance of Mg alloy, some AM50 samples are processed with Nd. glass pulsed laser. The experimental results show that plastic deformation occurred in the surface layer, density and hardness are improved, great compressive residual stress is formed, and the residual stress on the surface reaches 146 MPa with laser power density of 3 GW/cm2. The electrochemical polarization results show that the corrosion potential and pitting potential of the LSP sample increase by 64 mV and 92 mV as compared to the untreated sample, respectively, while the corrosion current density decreases about 88.6 %. After 20 hours continuous spraying in the salt spray environment, more and larger pits appear on the surface of untreated sample, and the corrosion area is reduced by 84.7 % after laser shot peening. The corrosion resistance of AM50 Mg alloy is improved markedly by laser shot peening.

关 键 词：激光技术 激光喷丸 AM50镁合金 耐蚀性能 极化曲线 盐雾试验 

分 类 号：TN249[电子电信—物理电子学] TG146.2[一般工业技术—材料科学与工程]