Microstructure and mechanical properties in nano and microscale SiC-included dissimilar friction stir welding of AA6061-AA2024

Abstract

This work investigates the effect of SiC particles on the microstructure and mechanical properties of dissimilar friction stir welding between AA6061-T6 and AA2024-T351. Two variations in the size of SiC particles, along the joint line, various groove width, and tool offset, were used for the welding. It was found that the joints made by rotational speed of 800 rev min⁻¹, travelling speed of 31.5 mm min⁻¹, groove width of 0.3 mm, and tool offset of 0.5 mm exhibited the most uniform distribution of particles for both micro- and nano-scale SiC particles. Additionally, the smaller and rounded equiaxed particles result in easier material flow, a more uniform metal matrix composite, the smallest grain size in the stir zone and the highest tensile strength.