Investigation of microstructure and mechanical characteristic of underwater friction stir welding for Aluminum 6061 alloy – Silicon carbide (SiC) metal matrix composite

Demand for metal matrix composites (MMCs) is expected to increase in these applications, such as ‎in the aerospace and automotive sectors. Adequate joining techniques, which are important ‎structural materials, have not yet been developed Metal Matrix Composite (MMCs), however. ‎This work aimed demonstrate feasibility of ‎friction stir welding (FSW) ‎underwater friction (UFSW) Al 6061/5, 6061/10, ‎‎6061/18 wt. %SiC produced by utilizing reinforce casting technique. Two ‎rotational ‎speeds,1000and 1800 rpm, traverse speed 10mm \ min were examined. Specimen ‎composite plates 10 mm thick successfully welded FSW. For FSW UFSW, a tool ‎made high-speed steel (HSS) with conical pin shape was used. The result revealed that ‎ultimate tensile strength joint UFSW at rotation rpm (Al ‎‎% SiC composites) 195 MPa 230 respectively. ultimate ‎tensile ‎strength 6061/18 wt.% SiCe 165 ‎and 180 ‎‎1000 microstructural assessment showed due ‎to larger grain sizes most fractures located thermal ‎mechanically affected zone (TMAZ) adjacent weld nugget (WNZ). It observed ‎failure, joints show ductile features. As volume fraction (18 wt.%) increases, ‎the underwater efficiency decreases.