Unveiling the heat‐resistant mechanism of an additively manufactured Ag– and Ti‐modified Al–Cu–Mg alloy

Abstract The rapid development of the space field has presented elevated requirements for the performance of lightweight structures under high‐temperature conditions, while the additive manufacturing of aluminum alloy for aerospace is faced with the problem of insufficient high temperature performance and cracking. To this end, we designed a novel Ti– and Ag‐modified Al–Cu–Mg alloy using laser powder bed fusion, which showed a high mechanical performance with a tensile strength of 426 MPa at room temperature and 314 MPa at 200 °C, greatly surpassing the majority of currently developed heat‐resistant Al alloys. The microstructural observation demonstrated that Ti element facilitates the formation of coherent L1 2 –Al 3 Ti particles, thereby contributing to grain refinement, while Ag segregates to the grain boundaries and forms small Ag 2 Al particles, which effectively enhance pinning effects. Additionally, Ag 2 Al particles at high temperature significantly contribute to the superior performance in elevated temperature conditions of the designed alloy. Thus, this study has developed a novel alloy with Ag and Ti elements addition and clarified the crucial role of Ag and Ti elements in modifying additively manufactured Al alloy, laying a foundation for the application of lightweight heat‐resistant components in the future.