飞秒激光冲击AZ31B镁合金过程的数值模拟  

Numerical Simulation of AZ31B Magnesium Alloy Shocked with Femtosecond Laser

作　　者：姚红兵[1] 于文龙[1] 杨昭[2] 李强[2] 高原[1] 李亚茹[1] 倪文强[1] 

机构地区：[1]江苏大学机械工程学院,江苏镇江212013 [2]连云港师范高等专科学校物理电子系,江苏连云港222006

出　　处：《光子学报》2015年第4期35-40,共6页Acta Photonica Sinica

基　　金：国家自然科学基金重点项目(No.50735001);国家自然科学基金(Nos.51405181;50735001;10804037);连云港市工业攻关项目(No.CG1315);中国博士后科学基金特别项目(No.200902506)资助

摘　　要：采用有限元分析法对飞秒激光冲击AZ31B镁合金进行数值模拟,研究了激光冲击处理对镁合金变形过程的影响,分析了单脉冲激光冲击下材料内部的位移、动能、应力和应变的分布情况,得到了材料的瞬态速度和应变率变化过程.仿真结果表明,单脉冲飞秒激光冲击镁合金产生的塑性变形,可在材料表面形成微米级凹坑,中心点处最大位移为34μm,最大变形速度390m/s;在冲击初期,材料表面的应力和应变主要分布在冲击区域中心节点和边缘附近,并且得到镁合金的最大应力和最大应变率分别为955 MPa和1.8×106 s-1.研究结果能够为深入分析飞秒激光与镁合金作用时材料变形参量的变化规律提供数值理论依据.The laser shocking processing of AZ31 Bmagnesium alloy sheet by the femtosecond laser pulse is numerically simulated with the finite element method.In the simulation,the effect of laser shock processing on the deformation process of AZ31 B magnesium alloy is studied,the distributions of characteristics within the material,such as displacement,stress and strain,are analyzed,and the dynamic variation process of velocity and strain rate is discussed.The results indicate that the plastic deformation of magnesium alloy sheet shocked by single femtosecond laser pulse led to a micrometer-scale pit on the material surface.The maximum displacement at the center of the pit is 34μm.And the maximum speed reaches 390m/s.Stress and strain of material aremainly distributed near the central dot and the edge of laser shocked region.The maximum stress of the central dot is 955 MPa,and the maximum strain rate reaches 1.8×10^6 s^-1.The results show that the numerical simulation of the laser shocking processing of AZ31 Bmagnesium alloy sheet by the femtosecond laser pulse is able to provide the numerical references for analysis of the variation laws of materials by femtosecond laser loading.

关 键 词：激光技术 飞秒激光 有限元分析 镁合金 特征量 板材成形 

分 类 号：TN24[电子电信—物理电子学]