Influences of pin profile on the mechanical and microstructural behaviors in dissimilar friction stir welded AA6082-AA7075 butt Joint

This paper investigates the effect of tool pin profile and post weld heat treatment on the mechanical and microstructural aspects of friction stir welded dissimilar precipitation-hardenable aluminum alloys between 6xxx (Al-Mg-Si) and 7xxx (Al-Zn-Mg). It was found that the tool with a conical probe with three grooves produces higher temperatures than the tool with a square frustum probe. The mixture of materials in the weld nugget of joints welded by the tool with the square frustum probe was more uniform. Of the natural aging times studied, the stir zone of all welds showed the highest kinetics of microhardness and strength recovery; its effect increased considerably in the heat input per unit length decreased.