Effect of Mo and V additions on the coarsening kinetics and high-temperature strength in γ′ precipitation-strengthened high-entropy alloys

Abstract

High-entropy alloys (HEAs) containing well-stabilized nano-precipitates have a huge advantage in elevated temperature applications. This study investigated the effects of Mo and V additions on the morphological evolution, the coarsening kinetics of multi-component γ′ precipitates, and the high-temperature tensile strength of HEAs. HEAs with the additions of Mo and V have significantly lower lattice misfit values and exhibit a smaller coarsening rate of γ′ nanoparticles compared to Ni and Co-based superalloys. Moreover, the precipitate morphology related to the lattice misfit exhibits completely different effects attributed to Mo and V addition. Remarkably, Mo2.5V2.5 HEA has a yield strength of 496 MPa at 800 °C, which shows great potential for high-temperature applications.