Relationship between local geometrical factors and mechanical properties for Cu–Zr amorphous alloys

CuxZr1−x (x = 0.30–0.85) amorphous alloy models were constructed using molecular dynamics simulations. In order to estimate the local structures characterized by pentagonal short-range order and free volume, Voronoi polyhedra analyses were performed for the initial states and also for the deformed states of the models. Both these geometrical factors are intimately related to each other and exhibit a large influence on mechanical properties. The elastic properties tend to increase as the free volume decreases. Moreover, flow stress drastically decreases with increasing free volume content. It was found that the non-pentagonal regions, which are sources for the generation of high free volume structures, preferentially undergo irreversible atomic rearrangements in the early stage of the deformation process.