### 6061铝合金超声电弧MIG焊声电特性和工艺

1. 1. 江苏大学 材料科学与工程学院, 镇江 212013;
2. 中广核研究院有限公司, 深圳 518000
• 收稿日期:2020-11-13 修回日期:2020-11-30 发布日期:2021-02-02
• 通讯作者: 雷玉成 E-mail:yclei@ujs.edu.cn
• 基金资助:
国家自然科学基金（51875264）

### Acoustic-electric characteristics and process of ultrasonic-arc MIG welding of 6061 aluminum alloy

LI Hongliang1, CUI Zhanxiang1, LIU Shixiong1, MA Qiang1, YAO Yiqiang2, LEI Yucheng1

1. 1. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China;
2. China General Nuclear Power Corporation, Shenzhen 518000, China
• Received:2020-11-13 Revised:2020-11-30 Published:2021-02-02
• Supported by:
National Natural Science Foundation of China

Abstract: The arc-ultrasonic welding technology is an effective method to refine the weld grain and improve the mechanical properties of joints. To study the excitation and function mechanism of ultrasonic in the arc-ultrasonic MIG welding process and better control the arc-ultrasonic, the MIG welding arc is modulated by the high frequency signal to excite the ultrasonic wave. The electrical and acoustic excitation characteristics of the welding arc are obtained through signal acquisition and analysis during the welding process. The approximate relationship between the input impedance of the welding arc, the sound pressure of the excited ultrasonic and the excitation parameters is preliminarily identified. The effect of arc-ultrasonic on weld appearance and weld metal microstructure is also clarified. It is concluded that external ultrasonic excitation causes the oscillation of welding arc voltage at the base value, and the input impedance of the MIG welding arc to the ultrasonic excitation is related to the excitation frequency. The greater the excitation frequency is, the lower the excited triangular wave current becomes, and then the larger the input impedance gets. The ultrasonic response frequency of the MIG welding arc shows a same value with the excitation frequency, while the ultrasonic sound pressure amplitude is related to the excitation energy. The smaller the excitation frequency is and the higher the excitation voltage is, the greater the excitation energy is, and the greater the ultrasonic sound pressure amplitude becomes. The introduction of ultrasonic arc can increase weld penetration. Compared to conventional MIG welding, the weld penetration obtained using the ultrasonic arc technique can be increased by 23% when Ue is 55 V and f is 70 kHz. The grain size of the weld metal is refined and the precipitates in the weld metal are more dispersed.