Effect of Ultrasonic Power on Microstructural and Mechanical Properties of Al/Cu Plasma Arc Welding-Brazing Joints

T2 copper was joined to 1060 pure aluminum by a novel welding method, that is, an ultrasonic-assisted plasma arc Welding-Brazing process. The impacts of ultrasonication on the interfacial microstructure and weld formation were studied. Optical microscopy and scanning electron microscopy were used to observe weld formation and the resulting microstructure. The elemental distributions and phase formation of the alloy were identified by energy dispersive spectrometry and x-ray diffraction. A tensile test machine was used to determine the shear strength of the weld lap joint. The results showed that ultrasonic vibration significantly improved the wetting and spreading ability of Al on the Cu substrate and changed the morphology of the intermetallic compound (IMC) layer. Ultrasound assistance can also significantly break the continuous IMC layer, and some bulk-shaped IMC phases were found in the weld. In studies of the mechanical performance of the weld joint, the shear strength did not increase linearly with ultrasonic power. When the ultrasonic power was 1400 W, the maximum shear strength of the welded joint reached 86.31 MPa, and the shear strength was 67.2% higher than that of the ultrasonic joint made without increasing the power.

Automated summary

In this study, T2 copper was joined to 1060 pure aluminum using an ultrasonic-assisted plasma arc Welding-Brazing process. The results showed that ultrasonic vibration significantly improved the wetting and spreading ability of aluminum on the copper substrate and changed the morphology of the intermetallic compound layer. The shear strength did not increase linearly with ultrasonic power.