Simultaneous Improvement Of Strength And Ductility Of Al-mg-si Alloys By Combining Equal-channel Angular Extrusion With Subsequent High-temperature Short-time Aging

摘要

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℃ 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.