镁合金在冷金属过渡电弧增材制造成形过程中的数值模拟  

Numerical simulation of magnesium alloy in CMT arc additive manufacturing forming process

作　　者：王天琪[1] 靖雯 何俊杰[1] WANG Tianqi;JING Wen;HE Junjie(School of Mechanical Engineering,Tiangong University,Tianjin 300387,China)

机构地区：[1]天津工业大学机械工程学院,天津300387

出　　处：《天津工业大学学报》2025年第1期83-90,共8页Journal of Tiangong University

基　　金：天津市科技特派员项目(20YDTPJC00780);天津市“项目+团队”重点培养专项资助项目(XC202053);天津市教委科研计划项目(2019KJ011)。

摘　　要：针对镁合金在冷金属过渡(CMT)电弧增材制造成形过程中熔池精度难于控制、结构件成形质量差等问题,建立了三维瞬态数值模型,研究了增材过程中的熔池流动及传热过程。引入周期性系数加入双椭圆热源中,得到了更加符合实际CMT焊接过程的热源模型,并利用连续表面力思想将其转化为体热源加载在相界面;预测了焊缝和熔池的形状和尺寸,并与试验结果进行了比较;计算了同一焊接速度下不同焊接电流对焊缝成形的影响。结果表明:熔池内部主要受马兰戈尼力影响在熔池后方产生逆时针流动;将模拟结果与试验进行对比发现,焊接电流为129 A时熔宽误差约为1.13%,余高误差约为5.49%,熔深误差约为5.03%,验证了模型的准确性;相同焊接速度下,随着焊接电流的增大,焊缝宽高比以及熔深均增加。A three-dimensional transient numerical model was established to address the issues of difficult control of molten pool precision and poor forming quality of structural parts during the cold metal transition(CMT)arc additive manufacturing of magnesium alloy.The flow and heat transfer of the molten pool during the additive manufacturing process were studied.A periodic coefficient was introduced into the double elliptic heat source to obtain a heat source model more consistent with the actual CMT welding process,and the continuous surface force was used to convert it into a body heat source loaded at the phase interface.The shape and size of the weld seam and molten pool were predicted and compared with experimental results.Furthermore,the effects of different welding currents on the weld seam formation at the same welding speed were calculated.The results show that the interior of the melt pool is mainly influenced by Marangoni forces,which produce counterclockwise flow at the back of the pool.The simulation results were compared with the experimental results,and when the welding current was 129 A,the error of melting width was about 1.13%,the error of residual height was 5.49%,and the error of melting depth was 5.03%,which verified the accuracy of the model.At the same welding speed,the ratio of weld width to height and the depth of fusion increase with the increase of current.

关 键 词：镁合金 冷金属过渡 熔池 焊缝成形 增材制造 

分 类 号：TG457.19[金属学及工艺—焊接]