Influence of Reinforcement with Multi-Pass FSW on the Mechanical and Microstructural Behavior of Dissimilar Weld Joint of AA5083 and AA6061

In the present study, a defect-free dissimilar weld joint of AA5083 and AA6061 was fabricated, and the influence of SiC particles with multi-pass friction stir welding (FSW) on the microstructural evolution and various mechanical behaviors was investigated. A constant tool rotational speed of 950 rpm, traverse speeds of 30 mm/min and tool tilt angle of 1° were used as welding parameters. The results revealed that increasing the number of FSW passes from one to three improved the particles dispersion, which improved the tensile strength, %elongation, and micro-hardness of the FSWed joint via the pinning effect. After implementation of one, two and three FSW passes, the tensile strength of the FSWed joints was observed as 244.31, 251.58 and 266.87 MPa, and the %elongation was observed as 27.4, 29.8 and 32.7%, respectively. Furthermore, the micro-hardness after one, two and three FSW passes was observed to be 116.4, 120.8 and 128.4 HV, respectively.