A study on thermo-mechanical analysis of ultrasonically welded dissimilar alloys for automotive application

Ultrasonic spot welding (USW) method has the capability to produce highly efficient solid-state bonds in lightweight alloys with minimum power consumption. Unlike fusion welding techniques, this technique utilizes less energy and produces superb joint quality with refined grain structures and minimal intermetallic compounds (IMCs). This method has been receiving attention progressively in the material joining field because of its advantages like environmentally friendly, shorter weld time, and involvement of low temperature. Thus, these properties make this process suitable for welding of malleable thin metal sheets. During the USW process, it is noticed that the effect of intensive material contact increases when the weld progresses, and it leads to the frictional heating and plastic deformation phenomena. Subsequently, it results in the change of mechanical and microstructural characteristics at the weld zone. To reduce the forming load and static stress distribution from the welded samples, it is necessary to analyze the thermo-mechanical properties of ultrasonically welded joints. In the current study, various aspects of ultrasonic energy on material deformation and temperature variations are investigated using the finite element analysis (FEA). As a result, several types of features are noticed in the weld region with different forming morphologies. To further explore the effect of weld process parameters on the weld interface of this dynamic process, the strength and fracture in USW are also studied. (C) 2021 Elsevier Ltd. All rights reserved.