TC4合金等离子–MIG复合焊过程温度场的数值模拟

目的 研究TC4合金在等离子-MIG复合焊(Plasma–MIG Hybrid Welding)过程中的温度场特性，探究不同电弧功率对熔池形貌的影响。方法 进行了2组4 mm TC4合金板堆焊试验，根据实验结果提出了一种改进的复合热源模型并进行了相应的仿真分析。结果 仿真与实验获得的焊缝截面相吻合;等离子电流的增大使熔池尺寸增大且余高减小，等离子电弧功率的变化对熔池宽度的影响相对较小。结论 等离子–MIG复合电弧对工件的热作用非常集中，更易实现深熔焊、焊接效率更高;所提出的热源模型适用于TC4合金等离子–MIG复合焊温度场模拟。

Simulation of Temperature Field in Plasma-MIG Hybrid Welding of TC4 Alloy

In order to investigate the temperature field of TC4 alloy during plasma MIG hybrid welding and the effect of arc power on weld pool shape, an improved hybrid body heat source model is proposed, which is capable of accurately characterizing the heat input of the hybrid arc on workpieces. Experiments on 4 mm Ti-6AL-4V plates in plasma-MIG hybrid welding surfacing and a corresponding simulation analysis were conducted. The calculated results of weld cross-section are in good agreement with the experimental results. The results show that, as plasma current increases, the size of the weld pool increases and the weld reinforcement decreases; the plasma arc power has less effect on the width of the weld pool. It is easier to fulfill deep penetration welding and high welding efficiency in plasma-MIG hybrid welding of Ti-6AL-4V alloy.