Nanowear of Zr-based metallic glasses regulated by cooling rate-induced heterogeneity

Enhanced plastic deformability of metallic glasses (MGs) can be achieved by increasing structural heterogeneity via optimized rapid cooling. However, the correlation between the nanotribological properties and intrinsic structural heterogeneity remains unclear for Zr-based MGs. In this work, Zr-based MGs with tailored atomic structures were prepared by controlling cooling rates, and nano-wear tests were conducted using advanced atomic force microscopy (AFM). The fast-cooled MG with higher structural heterogeneity exhibits increased adhesion and plowing frictions, but concurrently provides superior plasticity and anti-wear properties, despite a lower hardness. Molecular dynamics simulations and AFM energy dissipation tests reveal that the increased adhesion stems from the energy dissipation induced by pronounced structural heterogeneity, whereas the elevated plowing friction results from reduced hardness and elastic recovery. The superior plasticity of fast-cooled MG effectively dissipates the tip strain through the formation of multiple shear bands. The competition between the enhanced plasticity suppressing material delamination and increased plowing friction endows this Zr-based MG with exceptional nanoscale wear durability. These findings provide valuable insights for designing wear-resistant Zr-based MGs through nanoscale structural heterogeneity regulation.