(1. 江苏大学材料科学与工程学院，镇江212013；
2.上海交通大学，密西根学院，上海 200240)
摘 要: 为了研究激光冲击强化(LSP)对镁合金力学性能的影响，采用电子万能拉伸机和显微硬度测试仪研究AZ31和AZ80D-T6镁合金拉伸应力-应变曲线和显微组织。结果表明：经LSP处理后，AZ80-T6和AZ31合金的抗拉强度分别增加4.6%和15.7%，其表层硬度分别增加22.7%和31.8%；AZ31合金激光冲击强化效果比AZ80D-T6合金的更加显著，激光冲击产生高幅残余压应力和高密度孪晶以及细小片层状、短棒状或动态析出β相，晶粒细化形成超细晶，并讨论预时效β析出相对镁合金激光冲击强化的影响和拉伸断口特征。
关键字: 镁合金；激光冲击强化；应力-应变曲线；力学性能；显微组织
（1. School of Materials Science and Engineering，Jiangsu University, Zhenjiang 212013, China;
2. Joint institute, University of Michigan- Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:In order to study the effect of laser shock processing (LSP) on mechanical properties of magnesium alloys, the tensile stress-strain curves and microstructures of AZ31 and AZ80D-T6 magnesium alloys were investigated by electronic universal tensile machine and microhardness test. The results show that after LSP, the tensile strengths of AZ80-T6 and AZ31 alloys increase by 4.6% and 15.7%, the surface hardnesses increase by 22.7% and 31.8%, respectively. The strengthening effect of LSP on AZ31 is more significant than that on AZ80D-T6. The LSP generates high value residual compressive stress and high-density twins as well as the fine lamellar or short columnar or dynamic precipitation β phases. The grains are refined and the ultrafine grains are formed. The effect of pre-aged β precipitates on LSP strengthening effect and tensile fracture characteristics were discussed.
Key words: magnesium alloy; laser shock processing; stress-strain curve; mechanical property; microstructure
