Molecular dynamic simulation study of the structural anisotropy in Cu50Zr50 and Cu64.5Zr35.5 metallic glasses induced by static uniaxial loading within the elastic regime

The structural anisotropy in both Cu50Zr50 and Cu64.5Zr35.5 metallic glasses induced by various static uniaxial loads within the elastic regime was studied by molecular dynamic simulations. Constant tensile and compressive loads from zero up to 200 MPa below the flow stress were applied in the simulation. The degree of anisotropy was characterized using a second order contact fabric tensor. It is found that the degree of anisotropy within the elastic regime increases with the applied load following an exponential growth function. The most part of the structural anisotropy can be attributed to the Zr–Cu atomic pairs in Cu64.5Zr35.5 and Zr–Cu, Cu–Cu atomic pairs in Cu50Zr50. The evolution of the structural anisotropy associated with the Zr–Zr and Cu–Cu pairs exhibits complex behavior, which implies that the deformation mechanism and the dynamics of Cu50Zr50 and Cu64.5Zr35.5 metallic glasses under compressive loads may be quite different from those under tensile loads.

Research highlights▶ The structural anisotropy in both Cu50Zr50 and Cu64.5Zr35.5 metallic glasses induced by various static uniaxial loads within the elastic regime was studied by molecular dynamic simulations. ▶ The degree of anisotropy was characterized using a second order contact fabric tensor. ▶ The most part of the structural anisotropy can be attributed to the Zr–Cu atomic pairs in Cu64.5Zr35.5 and Zr–Cu, Cu–Cu atomic pairs in Cu50Zr50.