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 ± 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.