放电电压对镁-铝磁脉冲焊接中金属射流及结合界面的影响

Investigation on the Effect of Discharge Voltage on Metal Jet and Bonded Interface in Mg-Al Magnetic Pulse Welding

近年来,磁脉冲焊接技术凭借其在异种金属焊接中的独特优势展现出广阔的应用前景。放电电压是磁脉冲焊接过程中重要的电气参数,而金属射流可清理工件表面的污秽和氧化层,促进金属的冶金结合。为探究放电电压对金属射流及结合界面的影响,该文对放电电压与金属射流特征、结合界面形貌之间的内在联系进行理论分析,并建立镁-铝磁脉冲焊接综合实验观测平台,捕捉到完整的金属射流轨迹。结果显示,当放电电压从13kV提高到16kV时,碰撞速度从403.12m/s提高到了498.49m/s,对碰撞角度无明显影响;金属射流持续时间从31.02μs增加到47.94μs,且射流强度也逐渐增强。金相显微镜测试结果表明,放电电压为14kV、15kV、16kV时,镁-铝结合界面呈现波纹界面,且波幅不断增大,结合区域宽度分别为1.27mm、1.35mm、1.77mm。放电电压通过碰撞速度、碰撞点速度、碰撞压力及碰撞后剩余能量改变金属射流特征及结合界面形貌从而影响焊接效果。该文可为深入研究磁脉冲焊接机理、提高焊接效果提供有力参考。

In recent years,magnetic pulse welding(MPW)technology has shown a broad application prospect because of its unique advantages in welding dissimilar metals.The discharge voltage is an important electrical parameter in the EMPW process,and the metal jet can clean the surface of the metal and the oxide layer that promotes the metallurgical bonded of metals.To explore the effect of discharge voltage on the metal jet and the bonded interface,the relationship among the discharge voltage,the characteristics of the metal jet and the morphology of the bonded interface was studied,an integrated observation platform for the MPW process of the Mg and Al sheets was established,and the trajectory of the metal jet was captured.The results showed that when the discharge voltage was increased from 13 kV to 16 kV,the collision speed increased from 403.12 m/s to 498.49 m/s,but there was no significant effect on the collision angle;the duration of the metal jet increased from 31.02μs to 47.94μs,and the intensity of the metal jet also gradually increased.The metallographic microscope test results showed that when the discharge voltage was 14 kV,15 kV,and 16 kV,the Mg-Al bonded interface presented the wave interfaces,the amplitude increased continuously,and the bonded zone width was 1.27 mm,1.35 mm,and 1.77 mm,respectively.The discharge voltage changes the welding effect through the collision speed,the collision point speed,the collision pressure,and the remaining energy after the collision.This paper can provide a powerful reference for further study on the mechanism of EMPW and improvement of welding effect.