Strength-ductility synergy of deposited Al–Mg-Sc alloy with a homogeneous phase distribution brought by heat treatment

Post-processing is crucial for achieving high mechanical performance in deposited Al–Mg-Sc alloys. However, simultaneously enhancing strength and ductility is challenging. This study analyzed the effects of aging and solution + aging treatments on precipitation behavior and tensile properties, obtaining the alloy with excellent mechanical performance. The results indicated that aging treatment precipitated fine Al 3 Sc phases to enhance strength, while residual primary Al 6 (Fe, Mn) phases led to poor ductility due to dislocation clusters. Solution + aging treatment refined large-sized Al 6 (Fe, Mn) phases, and formed dense secondary Al 3 Sc phases to delay dislocation clustering during tensile, thereby achieving the better performance in strength-ductility synergy. Compared to the deposited alloy, ultimate tensile strength and elongation of alloy prepared through solution + aging increased by 17 % and 13 %, respectively. This study offers new insights into enhancing mechanical performance of aluminum alloys and expands the engineering applications of Al–Mg-Sc alloys.