Investigation of Process Parameters on the Mechanical Strength in Ultrasonic Metal Welding of Aluminum to Copper Dissimilar Joints

As a solid-state welding method, ultrasonic welding of metals is widely used in different industries to produce high-performance materials such as lithium-ion batteries. This research aims to investigate and optimize the variables of ultrasonic metal welding to reach a maximum joint strength. The influence of welding time, welding pressure, and oscillation amplitude on the maximum load of tensile-shear and T-peel tests of dissimilar ultrasonic metal welding of aluminum 1050 and copper (purity above 99.9%) having a thickness of 0.3 mm has been investigated. Design Expert software and response surface method (RSM) have been used to obtain the optimal mode of welding parameters and check their mutual effects on each other to achieve the maximum weld strength. The results indicated that time and pressure are of the most influential parameters directly affecting the maximum tensile-shear test load. Further, time, pressure, and amplitude are of the most influential parameters directly influencing the T-peel test load. Finally, the optimal parameters were determined to be a welding time of 1 s, a pressure of 5.4 bar, and a vibration amplitude of 55%. In the optimal state, the maximum load obtained from the tensile-shear and the T-peel tests was equal to 824.4 N and 156.6 N, respectively.