Correlation between deformation behavior and atomic-scale heterogeneity in Fe-based bulk metallic glasses

The correlation betweent deformation behavior and atomic-scale heterogeneity of bulk metallic glasses (BMGs) is critical to understand the BMGs' deformation mechanism. In this work, three typical [(Fe0.5Co0.5)(0.75)B0.2Si0.05](96)Nb-4, Fe39Ni39B14.2Si2.75P2.75Nb2.3, and Fe50Ni30P13C7 BMGs exhibiting different plasticity were selected, and the correlation between deformation behavior and atomic-scale heterogeneity of Fe-based BMGs was studied. It is found that the serrated flow dynamics of Fe-based BMGs transform from chaotic state to self-organized critical state with increasing plasticity. This transformation is attributed to the increasing atomic-scale heterogeneity caused by the increasing free volume and short-to-medium range order, which facilitates a higher frequency of interaction and multiplication of shear bands, thereby results in a brittle to ductile transition in Fe-based BMGs. This work provides new evidence on heterogeneity in plastic Fe-based BMGs from the aspects of atomic-scale structure, and provides new insight into the plastic deformation of Fe-based BMGs. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

This study investigates the correlation between the deformation behavior and atomic-scale heterogeneity of Fe-based BMGs. It is found that as plasticity increases, the serrated flow dynamics of Fe-based BMGs transform from chaotic state to self-organized critical state. The increase in atomic-scale heterogeneity facilitates a higher frequency of interaction and multiplication of shear bands, resulting in a brittle to ductile transition in Fe-based BMGs.