High strength and ductility of Al–Si–Mg alloys fabricated by deformation and heat treatment

Al–Si–Mg alloys with 7% and 12% (mass ratio) Si contents were subjected to friction stir processing (FSP), warm rolling (WR), and heat treatment. The effects of process routes on the microstructure and mechanical properties of the Al–Si–Mg alloys were studied. FSP could break the eutectic structure and lead to the uniform distribution of the generated fine Si particles in the two Al–Si–Mg alloys. WR could effectively decrease the porosity of the Al–Si–Mg alloys. T6 could lead to the precipitation of the β'′ phases in these alloys. The structure characteristics, including fine grain and second phases, uniformly distributed Si particles, high density of β'′ phases, and low porosity, resulted in the satisfactory mechanical properties of the Al–Si–Mg alloys after FSP, WR, and T6 treatments.