Abstract Scope |
Owing to their excellent yield strength preservation at elevated temperatures, refractory high-entropy alloys (RHEAs) have drawn increasing attention in seeking optimal mechanical performances and exploring the underlying physical foundations. However, the apparent brittleness at ambient temperature, the necessity of extensive thermo-mechanical processing, and the presence of catastrophic oxidation, still remain as serious challenges. Following the natural mixing tendency amongst all refractory elements, our previous study has detailed the exploration of a Ti-V-Nb-Hf RHEA family that exhibits promising tensile ductility at room temperature. In this presentation, we will expand the property design space of this RHEA system via Al alloying, aiming to address the following three topics: (1) how much intrinsic strengthening (or softening) is associated with Al alloying? (2) how will dislocation plasticity micro-mechanisms vary in response to Al alloying? and (3) how does Al modulate the phase stability and thereby precipitation pathways at intermediate temperatures? |