背反射增效激光X形焊缝焊接残余应力的数值分析  

Numerical analysis on residual stress of back reflection induced synergistic X-shaped laser welding

作　　者：李乐 王宏宇[1] 黄爱国[1] 丁瑞[1] LI Le;WANG Hongyu;HUANG Aiguo;Ding Rui(School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学机械工程学院,镇江212013

出　　处：《焊接学报》2018年第10期61-64,70,131,共6页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51372216);江苏省精密与微细制造重点实验室开放基金资助项目(KFA11250-04)

摘　　要：以1.5 mm厚的TC4钛合金薄板为对象,建立了背反射增效激光焊接成形过程的三维瞬态有限元模型,基于熔池温度场通过间接耦合方式获得了X形焊接成形的应力场.结果表明,在常规激光焊接仅能获得V形焊缝的激光工艺参数下,背反射增效激光焊接可获得对称性好的X形焊缝;同时,其焊缝上表面纵向残余应力与常规激光焊接基本一致,但其焊缝下表面纵向残余应力较常规激光焊接要大,且达到了上表面纵向残余应力相同的水平;此外,不同线能量下背反射增效激光焊纵向残余应力的变化很小,表明背反射增效激光焊接的线能量对其焊接残余应力影响的敏感度较低.Taking 1.5 mm TC4 titanium alloy sheet as an object,three-dimensional transient finite element model of back reflection induced synergistic laser weld was established theoretically and stress field of back reflection induced synergistic X-shaped laser weld was obtained by indirect coupling based on temperature field of the molten pool.The results show that the way of back reflection induced synergistic laser welding can obtain X-shaped weld under the laser processing parameters,while the way of conventional laser welding(without reflection plate on the back of sheet)only obtained V-shaped weld.Meanwhile,although the longitudinal residual stress on the upper surface of the weld was basically identical to conventional laser welding,residual stress on the lower surfaces of the weld was bigger than conventional laser welding and reached the same level as the upper surface.Moreover,the change of longitudinal residual stress of back reflection which induced synergistic X-shaped laser weld was very small with different line energy.It indicates that sensitivity of line energy to residual stress was relatively low.

关 键 词：背反射增效激光焊 残余应力 TC4薄板 数值模拟 线能量 

分 类 号：TG456.7[金属学及工艺—焊接]