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 Al3Sc phases to enhance strength, while residual primary Al6(Fe, Mn) phases led to poor ductility due to dislocation clusters. Solution + aging treatment refined large-sized Al6(Fe, Mn) phases, and formed dense secondary Al3Sc 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.