Microstructure characteristics and mechanical properties of the Cu/Al dissimilar joints by electric current assisted ultrasonic welding

作者：Liu, Jian^*; Cao, Biao^*

来源：JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, 2021, 297: 117239.

DOI：10.1016/j.jmatprotec.2021.117239

• Ultrasonic welding
• Electric current
• Intermetallic compounds
• Cu
• Al joints

Dissimilar joints of copper and aluminium alloy were generated by electric current assisted ultrasonic welding (EUSW). The microstructure characteristics and mechanical properties of Cu/Al EUSW joints were systematically investigated. The electric current promoted the plastic flow at the welding interface. The intermetallic thickness increased with electric current. The microstructure characteristics of Cu/Al joints welded by EUSW were compared with those of the Cu/Al joints welded by ultrasonic welding (USW). A thinner intermetallic compound layer could be obtained at the more fully material mixing during EUSW. The Cu/Al joints welded by EUSW displayed ultimate tensile strength 12% and fracture energy 21% greater than those of the Cu/Al joints welded by USW. The reasons for the improvement in mechanical properties of the Cu/Al EUSW joints have been discussed.