Atomic structure of Co92−xBxTa8 glassy alloys studied by ab initio molecular dynamics simulations. Issue 23 (6th August 2020)

• Record Type: Journal Article
• Authors: Ma, Di; Zhang, Jing; Di, Yaxin; Wang, Jianfeng; Guan, Shaokang; Zhang, Tao
• Is Part Of: International journal of quantum chemistry. Volume 120:Issue 23(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-06
• Subjects: ab initio molecular dynamics simulations -- atomic structure -- cobalt alloys -- metallic glasses; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.26406
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: The ab initio molecular dynamics simulations were adopted to study the atomic structures of Co92− x B x Ta8 ( x = 30, 32.5, 35, 37.5, at%) glassy alloys. The results showed that the local packing of B‐centered clusters was more efficient than that of Co‐ and Ta‐centered clusters. It was also found that B‐centered clusters were the primary structure‐forming clusters. The Kasper polyhedra with a Voronoi index of <0 3 6 0> and <0 2 8 0> are dominant in B‐centered clusters. The <0 3 6 0> clusters could especially be formed into a robust network structure, which plays a key role in the increase of mechanical properties. Such a network structure has a higher activation barrier for structural rearrangement and a larger resistance to plastic flow. Thus, the increase in the fraction of <0 3 6 0> with B content would result in an increase in yield strength, as well as a sharp decrease in compressive plasticity. Abstract : Although, some researchers have studied the properties of glassy alloys from the atomic scale short program structure and medium program structure, the relationship among the composition, atomic structure and properties of the glassy alloys is not clear. In order to improve the efficiency of glassy alloys development, the effects of short atomic program and medium program on the properties of CO ‐B‐based bulk amorphous alloy will be considered in this study.