Atomistic Study on the Mechanical Behaviors of Nanoporous Glassy Alloys under Shear Loading: Effects of Porosity and Specific Surface Area

Abstract

Nanoporous glassy alloys (NPGAs) have recently garnered considerable interest across various disciplines due to their exceptional and tailored functional properties. The practical applications of NPGAs necessitate a deep understanding of their mechanical behaviors under various types of loads, yet research on their mechanical responses under shear loading remains insufficient. Herein, the mechanical properties and deformation mechanisms of representative Cu50Zr50 NPGA under shear loading are investigated through molecular dynamics simulations. The results demonstrate that the relationship between the shear modulus and the solid fraction of NPGA can be well described by a modified Gibson–Ashby scaling law . The shear yield strength is linearly proportional to the solid fraction. During shear deformation, two major cracks are triggered from the two free surfaces due to the drastic strain concentration. The two cracks then propagate along the loading direction with some deflections. Eventually, the NPGA sample fractures once one crack penetrates the sample entirely. The sensitivity of shear strength to strain rate is significantly lower than the sensitivity of tensile strength to strain rate. As the temperature increases, the shear modulus, shear yield strength, and ultimate shear strength decrease monotonically.