An additively manufactured heat-resistant Al-Ce-Sc-Zr alloy: Microstructure, mechanical properties and thermal stability.

In this study, a high-strength and heat-resistant Al–Ce–Sc–Zr alloy was designed and fabricated by additive manufacturing. The as-built alloy shows an excellent combination of strength and ductility compared to other Al–Ce-based alloys, including an ultimate tensile strength of 445 MPa, a yield strength of 344 MPa and an elongation of 10%. Even at 300 °C, the alloy still retains a superb tensile yield strength of 233 MPa, which is the best among the high-temperature aluminum alloys reported so far. The excellent performance is mainly attributed to a significant amount of fine, homogeneous and coarsening-resistant Al 11 Ce 3 intermetallic nanoparticles formed during the rapid solidification process of laser additive manufacturing. The formation of coherent Al 3 (Sc, Zr) nano-precipitates and interfacial segregation at the interface of intermetallic nanoparticles during high temperature exposure further improve the high temperature properties of the alloy. Our work has the potential to provide design concepts for the development of novel high temperature aluminum alloys. • The rapid cooling rates during additive manufacturing produce a high volume fraction of nanoscale Al 11 Ce 3 intermetallic. • Thermal exposure promotes the precipitation of Al 3 (Sc, Zr) in matrix and the segregation of Sc/Zr at Al/Al 11 Ce 3 interface. • The combined role of Al 11 Ce 3 intermetallic and Al 3 (Sc, Zr) nano-precipitates contributes to excellent mechanical properties. • The Al–Ce-Sc-Zr alloy exhibits a high tensile yield strength of 233 MPa at 300 °C. [ABSTRACT FROM AUTHOR]