Simultaneous improvement of strength and ductility of Al-Mg-Si alloys by combining equal-channel angular extrusion with subsequent high-temperature short-time aging

The aging behaviour after room temperature (RT) equal-channel angular extrusion (ECAE) of the pre-ECAE solid-solution treated 6060 Al alloy was investigated in wide ranges of temperature, time, and ECAE pre-strain. It is shown that high-temperature, short-time aging is most effective in improving both strength and ductility. Compared to the commercially available peak aged condition with coarse grains, an increase of ∼35% in both ultimate tensile strength and uniform elongation was obtained after one extrusion and aging at 170 °C for 18 min. Competing recovery and precipitation activity play a significant role in enhancing the ductility of Al-Mg-Si alloys. This work demonstrates a strategy for an efficient processing of UFG Al alloys with outstanding mechanical properties.