Numerical, experimental analysis and parametric optimization on friction stir spot welding of AA1100

Abstract

In order to replace steel with aluminum in the structure of automobile bodies, it is necessary to explore joining methods that can be used efficiently. The present work deals with the optimization of process parameters of friction stir spot welding for aluminum alloy and comparing the result with the conventional joining methods. The effect of process parameters such as rotational speed, Dwell time, plunging depth and tool pin type were focused to show the effect of each parameter on the tensile shear strength of the joint. The physical observation, software analysis, and experimental testing methods were considered to achieve the goal of this study. To make reliable predictions about the welding process parameters to be optimized the analytic models were performed based on a sound physical understanding of the process. Finite element simulation had been implemented on ABAQUS2019 software to predict the maximum temperature. Sixteen sets of experiments were conducted on the conventional vertical milling machine. The number of experiments was determined by using the response surface optimal custom design approach in Design-Expert software. The workpiece material was AA1100 with a dimension of 153 mm x 25 mm x 2 mm to weld underlap joint, the chemical composition of the workpiece was shown in this paper. The tensile shear strength of the joint was tested on the tensile testing machine and the result compared with the conventional joining methods. The friction stir spot welded joints had a better strength than the others. A practical experiment on riveting was conducted for comparison of results and the data of resistance spot welding was taken from the investigator's report. Finally, the results from the tensile test were optimized to identify the best levels of process parameters for the maximum tensile shear load.