镁合金/钢激光诱导电弧复合焊接模拟及分析

Simulation and Analysis of Magnesium Alloy/Steel by Laser-Induced Arc Hybrid Welding

以镁合金/钢对接接头为研究对象,选用组合热源模型模拟激光诱导TIG电弧复合热源的作用,考虑激光与TIG电弧的耦合效应及Fe-Ni固溶区的形成,利用ANSYS软件对焊接温度场分布和热循环曲线进行模拟计算。结果表明:所得模拟结果与实验结果吻合良好,验证了所建热源模型的准确性及适用性;镁合金/钢对接焊接头的峰值温度可达2249℃,焊接高温作用于镍夹层及其邻近的钢母材,促进了界面的冶金反应及元素扩散,为Fe-Ni固溶区、高熔点AlNi相及双固溶体结构界面层的形成提供了温度条件;液态镁合金熔池停留时间为0.28 s,能保证其在钢侧进行充分的润湿铺展,实现接头的良好成形;在熔池的搅拌作用下,AlNi强化相弥散分布,使得镁合金焊缝的强度增大。

In this study,a magnesium alloy/steel butt joint was taken as research material.A combined heat source model was implemented to simulate a laser-induced tungsten inert gas(TIG)hybrid welding heat source.The coupling effect between the laser and TIG and the formation of Fe-Ni solid solution zone were analyzed.ANSYS software was employed to simulate the welding temperature distribution and thermal cycle curve.Simulation and experimental results were in good agreement,verifying the accuracy and applicability of the proposed heat source model.The peak temperature of the joint reached 2249℃,and the Ni interlayer and adjacent steel base material were exposed to a high temperature,promoting interfacial metallurgical reaction and element diffusion and providing the temperature condition for the formation of Fe-Ni solid solution zone,AlNi phase,and an interface layer with a double solid solution structure.The residence time of the magnesium alloy molten pool was 0.28 s,which ensured that the liquid magnesium alloy could be fully wetted and spread on the steel and eventually achieved good joint formation.Under the agitation of the molten pool,the strength of the magnesium alloy weld was enhanced by dispersion distribution of strengthening phase AlNi.