Experimental investigation on impact energy of friction stir welded aluminum and copper dissimilar joint using full factorial method

Abstract

This research work carried out friction stir welding (FSW) of dissimilar aluminum AA3003-H12 and copper C12200-H01, with wide application in the refrigeration and heat exchanger industry. The main aim of this study is to investigate the influence of process parameters, i.e. pin type (PT), weld speed (WS), rotational speed (RPM), and shoulder diameter (SD) on impact energy (IE) of Al-Cu welded joint. The experimental study used the full factorial method with mixed levels of process parameters. Analysis of Variance (ANOVA) determines the significance of process parameters on impact energy. The results of the analysis of variance (ANOVA) shows that rotational speed (RPM) is the most influential process parameter contributing to the impact energy (IE) of dissimilar Al-Cu weld joint. The response optimizer tool in Minitab 18 software gives optimum weld conditions of process parameters for better weld performance. The FSW experiment with a tapered pin, weld speed of 16 mm/min, rotational speed of 1120 rpm, and shoulder diameter of 22.5 mm obtained the maximum impact energy value of 6.5367 J. The fine-grain recrystallization formed intermetallic compounds in the stir zone (SZ). These intermetallic compounds give a maximum microhardness of 382.24 Hv (0.1). The microstructure analysis of the stir zone (SZ) shows an equiaxed grain structure on the Cu side, while the Al side shows a fine recrystallized grain structure.