THE EFFECT OF ROTATIONAL SPEEDS ON THE MECHANICAL PROPERTIES OF DISSIMILAR FRICTION STIR WELDING FOR COMMERCIALLY PURE ALUMINIUM AND COPPER

Abstract

In this study, dissimilar sheets of commercial pure aluminum and copper, 4 mm thickness were butt joined by Friction Stir Welding (FSW) to experimentally explore the effect of tool rotational speeds on the mechanical properties. Three rotational speeds of 1200, 1700 and 2200 rpm were applied. The transverse speed and the axial force were kept constant at 50 mm/min and 5 KN, respectively. X-ray diffraction (XRD), Vickers microhardness and tensile strength were investigated at these different rotational speeds. The joint welded at 1700 rpm was compared with their counterparts and observed significantly better. The formation of relatively hard brittle intermetallic compounds AlCu and Al4Cu9 were observed with the joint fabricated at rotational speed of 2200 rpm. The results of microhardness (HV) at the nugget zones (NZ) were superior to those of thermomechanically affected zones (TMAZ), heat affected zones (HAZ) and the base metals (BM).