A review of additive manufacturing heat-resistant aluminum alloys: Materials, properties and strengthening strategies at high temperature

As high-speed aircraft, aerospace engines and other advanced equipment are developing towards lightweight, complex structures and higher heat resistance, additive manufacturing (AM) heat-resistant aluminum (Al) alloys that can operate at 200–400 °C are receiving significant attention. However, traditional heat-resistant Al alloys are not suitable for AM, so the research on AM-specific heat-resistant Al alloys is currently a new research hotspot, and related processes, materials and mechanism studies are constantly emerging. This paper provides a comprehensive review of the most recent advancements in the AM heat-resistant Al alloys. Firstly, the development status and high temperature mechanical properties of heat-resistant Al alloys in different series were reviewed, especially the novel systems such as Al-Ni, Al-Fe and Al-Ce, which exhibit excellent performance in proper composition (≥100 MPa at 400 °C). Secondly, on the basis of the reported literature, this paper comprehensively discusses the general heat resistance mechanisms and outlines a series of theories for improving thermal stability, including multi-component synergistic effect and atomic-scale segregation strengthening. Finally, the future research is prospected, with the hope that this work will serve as a valuable reference for the ongoing development of heat-resistant Al alloys.