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 Al11Ce3 intermetallic nanoparticles formed during the rapid solidification process of laser additive manufacturing. The formation of coherent Al3(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.