Altering the Metastable Wear Performance of Metallic Glasses via Mixing Entropy Regulation

Metallic glasses (MGs), with outstanding hardness, often show controversial wear behaviors and properties owing to their metastable structural features; however, a poor understanding of how the structure controls these behaviors impedes effective solution strategy proposals. Here, this study integrates experiments and simulations to uncover the metastable atomic structural evolution characteristics for macroscopic wear behavior and demonstrate that a high mixing entropy can tune the structural evolution and elevate the wear behavior of MGs. The results show that the order-of-magnitude improvement in wear performance is independent of the wear conditions (load or frequency) and MG hardness. The high mixing entropy regulates the local atomic preference clusters and retards the wear-induced local atomic rearrangements, thereby effectively alleviating the structural softening and devitrification behavior during the wear process. The findings have implications for understanding the wear mechanism at the atomic structural level and may open up new possibilities for designing advanced MGs with desirable properties based on entropy effects.