Development and validation of finite element model of dissimilar friction crush welding for automotive applications

Several present-day applications require the joining of dissimilar materials by solid-state processes. Aluminum-stainless steel sheet metal joining finds its application in the Automotive industry. In present work, two dissimilar sheet metal workpieces of Aluminium and Stainless Steel were joined with a newly developed Friction Crush Welding (FCW) process. Macro-structure images along with an X-ray diffraction (XRD) pattern were used to investigate the prepared samples, and a hook-like structure was found along with a U-shaped interface and intermetallic phases such as FeAl₂, Fe₂Al₅, FeAl₃, Al, and ϒ-Fe. The work aims to develop a novel Finite Element (FE) model based on ABAQUS for FCW of Aluminium-Stainless Steel. The FE model was developed as a three-dimensional, explicit nonlinear model utilizing the Lagrange technique. The developed FE model was validated by comparing the FE model results with experimental temperature data obtained by infrared thermography. The predicted temperature values from the FE model are in excellent agreement with the experimentally measured values. The influence of welding variables, i.e., tool rotational speed (2000, 3000, and 4000 rpm) and welding speed (15, 30, and 45 mm/min), on temperature, was also investigated. It was found that increasing tool rotational speed increases temperature but decreases stress distribution, whereas the correlation between feed rate and temperature was inversely proportional. Results show that the best weld structure was obtained when welding was performed at a welding speed of 30 mm/min and tool rotational speed of 3000 rpm. The developed FE model may be used to predict the temperature and weld structure.