Orientation dependent plasticity of metallic amorphous-crystalline interface

• Published in: Computational materials science 2018-01, Vol.141, p.375-387
• Main Authors: Alishahi, Ehsan, Deng, Chuang
• Format: Article
• Language: English
• Subjects: Amorphous-crystalline interface; Dislocation nucleation; Molecular dynamics simulation; Shear localization
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2017.09.057

[Display omitted] •Amorphous-crystalline interface (ACI) was studied as a novel type of planar defect.•The ACI structure and energy does not vary significantly with the crystalline orientation.•The deformation and plasticity at ACI strongly depends on the crystalline orientation. In this study, the influence of crystalline orientation on the plasticity of metallic amorphous-crystalline interface (ACI) has been investigated in a model system of crystalline Cu-amorphous CuZr multilayers by molecular dynamics simulations. It is found that the ACIs with various crystalline orientations all show similar structure with a gradual transition from crystalline to amorphous. As a result, the energy of ACIs shows only a weak dependence on the crystalline orientation. Additionally, the ACI shows no stress concentration or area of high energy than the rest of the materials. Those findings are in contrast to other types of planar defects such as grain boundaries or free surfaces. However, the strength and the yielding behavior vary significantly among the different amorphus-crystalline (A-C) multilayers. Specifically, it is found that the yielding mechanism, e.g., through dislocation nucleation in the crystalline Cu or through shear localization in the amorphous CuZr layer, is mainly determined by the crystalline orientation. What is more, the simulations on ACIs with polycrystalline Cu suggest that the plasticity of A-C multilayers strongly depends on the texture orientation of the columnar grains in the Cu layer, which can be used to explain some of the experimental observations on similar materials.