Defects Formation and Microstructure Characterization of Friction Stir Welded Al 6061 Plates

Abstract

Microstructure characterization and defects formation of a joint fabricated by friction stir welding on two plates of Al 6061 were studied. In this study, plates were in the height of 2mm and input parameters were pin profile (square and cylindrical shape), rotating speed (800 and 1600 rpm) and traverse speed (40, 80 and 120 mm/min). Also, some experiments were conducted and the effects of input variables on the microstructure of the samples are studied by using an optical microscope. Based on the results, a sound defect-free weld could be achieved by optimizing the ratio of traverse speed to rotational one, due to the influence of this ratio on the amount of heat generated during the FSW process. It has been also concluded that higher ratios of traverse speed to rotating speed can result in poor welds.