A study on mechanical and microstructural properties of dissimilar FSWed joints of AA5251–AA5083 plates

Abstract

This paper investigates the influence of rotational and travel speed on the structure and mechanical properties of different regions of friction stir welded dissimilar AA5251–AA5083 joints. It was observed that increasing rotational speed from 800 to 1 250 rpm, at a fixed travel speed, increased the grain size from 6.31 μm to 10.64 μm. This stemmed from higher heat input which is generated at higher rotational speed. Furthermore, it was discovered that at 1 000 rpm, 115 mm min ⁻¹ and also 1 250 rpm, 85 mm min ⁻¹, defect-free welds were produced. The results of tensile testing revealed that the best consistent tensile strength was produced at 1 000 rpm rotational speed and 115 mm min ⁻¹ travel speed with an average value of about 200 MPa. Further, the results clearly showed that the hardness values gradually increase from the 5251 aluminum side to the 5083 aluminum side.