Atomistic aspects of the Cu46Zr54 metallic glass under compressive deformation by molecular dynamics simulations

We present molecular dynamics simulations results on the response of the Cu46Zr54 metallic glass under compressive deformation. It came out that the system, which was initially consisted of 23% small icosahedral clusters (ICO) embedded in an amorphous matrix that is composed by local ICO fragments, distorted ICOs and truncated octahedral clusters, upon compressive solicitation is gradually transformed in a locally more ICO-like structure at expense of the amorphous matrix. This process results in a very dense glassy system that can sustain compressive strain by as much as 100%. In addition, we found that this behavior does not depend on the applied strain rate, which nevertheless affects the yield and the fracture stress. The obtained results provide insight on the deformation mechanisms acting for the accommodation of compressive deformation of this model system and could help in the design of new metallic glasses. (C) 2008 Elsevier B.V. All rights reserved.