Entropy‐Engineered Aluminum‐Based Superalloys with Superior High‐Temperature Mechanical Properties

Abstract

In the quest for lightweight high‐performance metallic materials in transportation, the limitations of high‐strength Al‐based alloys in high‐temperature (HT) applications have posed a significant challenge. To overcome this long‐standing bottleneck, an innovative design strategy, combining entropy‐driven compositional design and rapid solidification processing, to develop “Al‐based superalloys” with a γ/γ′ duplex microstructure reminiscent of Ni‐based superalloys is presented. By incorporating multirefractory elements (Ti, Zr, Hf, Nb, and Ta) into the alloy design, a high‐volume fraction of thermally stable coherent γ′ phase for strengthening the Al‐rich face‐centered cubic matrix from room temperature (RT) to temperatures close to the melting point is achieved. The developed Al‐based superalloys exhibit exceptional specific yield strength and specific Young's modulus, surpassing aerospace aluminum, cobalt, nickel, and titanium alloys from RT to HT. Moreover, our ultra‐strong alloys demonstrate deformability and exhibit fine‐dimpled fracture behavior. The versatility of our fundamental research on Al‐based superalloys demonstrates their potential and can inspire further research in this field. This work opens new possibilities for the development of next‐generation lightweight alloys with novel microstructures and outstanding mechanical properties.