背反射增效激光焊接熔池匙孔相变及流场分析  

Analysis on keyhole phase change and flow field of back reflection induced synergistic laser weld

作　　者：王宏宇[1] 丁瑞[1] 黄爱国[1] 阚鹏 崔万里[1] 

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5期125-128,共4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：建立了背反射增效激光焊焊接熔池流动中气相区、液相区和固相区的统一模型,在模型中考虑了等离子体/蒸气云和小孔吸收机制,综合了表面张力、热浮力和重力的作用.基于数值计算得到了熔池的三相匙孔相变以及流场,重点分析了表面张力对熔池流动和传热的影响.此外,通过钛合金薄板的背反射增效激光焊接试验对模型进行了验证.结果表明,匙孔引发等离子体/蒸气云与背面垫板诱发羽辉的耦合作用,是X形焊缝熔池形貌形成的主要原因;同时,表面张力是形成背反射增效激光焊接熔池内"椭圆回流环"的主要驱动力.An unified model of gas phase area,liquid phase area and solid phase area during the molten pool flow process of back reflection induced synergistic laser welding was established. Plasma & vapor cloud and keyhole absorption were considered and effects of surface tension,thermal buoyancy and gravity were taken into account in the model. The three-phase keyhole phase change and flow field of molten pool were obtained by numerical calculation,surface tension effect on flow and heat transfer of molten pool was mainly discussed. Moreover,a validation experiment of back reflection induced synergistic laser welding was carried out by taking titanium alloy sheet as an example. Results show that the coupling effect of plasma & vapor cloud caused by keyhole and back plume induced by back subplate is the main reason for the formation of X-type weld,and surface tension is the main driving force of the"oval reflux ring"formation in the back reflection synergistic laser welding molten pool.

关 键 词：激光焊接 背面羽辉 数值模拟 匙孔相变 流场 

分 类 号：TG456.7[金属学及工艺—焊接]