Research Progress on Process Optimization of Ultrasonic Spot Welding for Metals
As a solid-state connection technology with low temperature,low energy consumption and high efficiency,ultrasonic spot welding(USW)can realize the connection of similar and dissimilar metals of Al,Cu and Ti,which are difficult to be prepared by traditional welding methods,and it has a broad application prospect.The tensile strength is one of the most important indicator for evaluating the quality of USW,which can be influenced by numerous and complex factors.This paper focused on the internal relationship between the process design of USW and the joint strength,and the research progress of improving strength was introduced from the following five aspects:sonotrode tip design,metal pretreatment,welding parameters,addition of metal interlayer and hybrid welding.Finally,the research direction was proposed to provide feasible ideas for further improving the joint strength.