Molecular dynamics study on the effect of cooling rate on the mechanical behavior of B2-CuZr enhanced bulk-metallic glass composites

Abstract Metallic glasses (MG) have attracted considerable attention due to their high hardness, high fracture strength, and excellent corrosion resistance. However, their poor room-temperature plasticity limits their widespread application to some extent. To address this issue, researchers have attempted to introduce crystalline phases into MG to enhance their mechanical properties. Molecular dynamics (MD) simulations are a powerful tool for investigating the properties and deformation mechanisms of amorphous/crystalline dual-phase composite materials. In this study, MD simulations were employed to explore the effect of different cooling rates on the tensile properties of B2-CuZr enhanced bulk-metallic glass composites (BMGCs). Molecular dynamics simulations were conducted on B2-CuZr enhanced BMGCs at an ambient temperature of 300 K. The results indicate that as the cooling rate decreases, from 100 K/ps, 10 K/ps, 1 K/ps, 0.5 K/ps, the content of 〈0,0,12,0〉 polyhedra increases, resulting in improved mechanical strength but reduced plasticity. In this study, as the cooling rate increases from 0.5 K/ps to 100 K/ps, the deformation strain increases from ε = 0.407 to ε = 0.466. However, the specimens with a cooling rate of 1 K/ps display notably better plasticity, deviating from the trend. This enhancement in plasticity is attributed to the increased presence of 〈0,2,8,5〉 polyhedra in the 1 K/ps sample. The findings of this study provide valuable insights for the design and fabrication of high-performance metallic glass materials.