Impact of hydrogen microalloying on the mechanical behavior of Zr- bearing metallic glasses: A molecular dynamics study

BB Wang and LS Luo and FY Dong and L Wang and HY Wang and FX Wang and L Luo and BX Su and YQ Su and JJ Guo and HZ Fu, JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 45, 198-206 (2020).

DOI: 10.1016/j.jmst.2019.11.027

Comparative studies on Zr35Cu65 and Zr65Cu35 amorphous systems were performed using molecular dynamic simulations to explore whether their hydrogenated mechanical behavior depends on the content of hydride- forming elements. Although both of them present an increased strength and ductility after hydrogen microalloying, we observe the improved mechanical behavior for Zr35Cu65 is more pronounced than that for Zr65Cu35. In these two samples, the distribution of configurational potential energy and flexibility volume respectively follows a similar H-induced variation tendency; all of the hydrogenated alloys not just have more stable atoms with smaller flexibility volume, but possess a larger fraction of readily activated atoms. However, the atomic-scale details, based on the local "gradient atomic packing structure" model, indicate minor additions of hydrogen can promote more "soft spots" along with more strengthened "backbones" in the low-Zr alloy than that in the high-Zr sample, which endows the former with much higher strength and deformability after hydrogen microalloying. We regard this finding as a further step forward to distilling the tell-tale metrics of the H-dependent mechanical behavior observed in Zr-based metallic glasses. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

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