Synergetic enhancements on the mechanical and tribological performance of Al${}_{10}$CR${}_{17}$Fe${}_{20}$NiV${}_4$ medium-entropy alloys induced by nano-Al${}_2$O${}_3$ particles

Due to the lack of mature mechanisms to support the wear performance of medium-entropy alloys (MEAs) with nonequiatomic ratios, the practical application of medium alloy in wear-resistant structural materials is severely restricted. Herein, a nonequiatomic Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$ medium entropy reinforced by nano-Al${}_2$O${}_3$ particles is designed and fabricated through high-energy ball milling and hot pressing. During the high-energy ball-milling process, a supersaturated solid solution with a single face-centered cubic structure is formed in the Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$. The hardness of Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$-reinforced Al${}_2$O${}_3$ nanoparticles is 13.9 /pm 0.4 GPa measured using nanoindentation, which is about twice high as that of MEAs. Both Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$ and Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$-Al${}_2$O${}_3$ are implemented to ball-on disc sliding wear at ambient temperature against an alumina ball and Si${}_3$N${}_4$ ball. The wear test indicates that the wear rate of Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$-Al${}_2$O${}_3$ against Al${}_2$O${}_3$ and Si${}_3$N${}_4$ is 13.87 × 10${}^{-5}$ and 9.47 × 10${}^{-5}$ mm${}^3$ N${}^{-1}$ m${}^{-1}$, which is lower than those of the Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$, respectively. The significant enhancements in the mechanical and wear performance can be mainly due to the coupled effects of grain refinement and particle dispersion strengthening induced by nano-Al${}_2$O${}_3$ particles. The enhanced mechanical and wear properties of Al${}_{10}$Cr${}_{17}$Fe${}_{20}$NiV${}_4$ make it a competitive candidate to be applied in advanced mechanical manufacturing. (© 2022 Wiley‐VCH GmbH)