Improvement of mechanical properties of a cryorolled Al-Mg-Si alloy through warm rolling and aging

The Al-Mg-Si alloys with and without pre-aging treatment were subjected to cryorolling, warm rolling and subsequent aging. Mechanical behavior and microstructural evolution were investigated by tensile tests, differential scanning calorimetry, X-ray diffraction and transmission electron microscopy. Tensile results showed that the strength and ductility of the cryorolled alloy were simultaneously enhanced by warm rolling and aging. After final aging, the pre-aged alloy exhibited better combination of strength and ductility than the alloy without pre-aging. Microstructural results demonstrated that pre-aging treatment was beneficial for the formation of strengthening phases during warm rolling and final aging, which accounted for the improved strength. The presence of finely dispersed nano-precipitates as well as a decrease in dislocation density played an important role in good ductility. (C) 2018 Elsevier B.V. All rights reserved.