Qiao Junnan, Wu Chuansong, Li Yongfeng
MOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan 250061, China.
Materials (Basel). 2021 Feb 2;14(3):703. doi: 10.3390/ma14030703.
The acoustic radiation force driving the plasma jet and the ultrasound reflection at the plasma arc-weld pool interface are considered to modify the formulas of gas shear stress and plasma arc pressure on the anode surface in ultrasonic-assisted plasma arc welding (U-PAW). A transient model taking into account the dynamic changes of heat flux, gas shear stress, and arc pressure on the keyhole wall is developed. The keyhole and weld pool behaviors are numerically simulated to predict the heat transfer and fluid flow in the weld pool and dynamic keyhole evolution process. The model is experimentally validated. The simulation results show that the acoustic radiation force increases the plasma arc velocity, and then increases both the plasma arc pressure and the gas shear stress on the keyhole wall, so that the keyholing capability is enhanced in U-PAW.
在超声辅助等离子弧焊（U-PAW）中，驱动等离子体射流的声辐射力以及等离子体电弧熔池界面处的超声反射被认为会修正阳极表面气体剪切应力和等离子体电弧压力的公式。建立了一个考虑小孔壁上热通量、气体剪切应力和电弧压力动态变化的瞬态模型。对小孔和熔池行为进行了数值模拟，以预测熔池中的传热和流体流动以及动态小孔演变过程。该模型经过了实验验证。模拟结果表明，声辐射力增加了等离子体电弧速度，进而增加了小孔壁上的等离子体电弧压力和气体剪切应力，从而增强了U-PAW中的小孔形成能力。
