Effect of rotational and traversal speeds on microstructure and mechanical properties of friction stir-welded 7075-T6 aluminium alloy

In this article, effects of rotational and traversal speeds on the microstructure and mechanical properties of friction stir-welded 7075-T6 Al alloys were investigated. Good correlation existed between the rotational and traversal speeds and weld properties. It was found that with increase in the rotational and traversal speed, wider thickness of the heat-affected zone were obtained, and then grain coarsening, dissolution, and accumulation of hardening precipitates in grain boundaries. In addition, the highest toughness during tensile test was obtained at moderate rotational and traversal speeds of 325 r/min and 30 mm/min. However, the highest microhardness was obtained at moderate rotational and traversal speeds of 325 r/min and 60 mm/min. It was imposed high temperature which cause of this different.

Keywords:

Friction stir welding , 7075-T6 Al alloy , rotational speed , mechanical properties , Microstructure