The influence of isothermal annealing on the strain rate sensitivity (SRS) of a Zr-based bulk metallic glass (BMG) was investigated by nanoindentation. A more positive SRS is observed with a decrease in the content of the free volume (FV) of the sample. Furthermore, the SRS becomes nearly constant with increasing annealing time when the FV is annealed out. By taking into consideration the FV-assisted activation and combination of the shear transformation zones (STZs), the underlying mechanism is well understood. The current work may offer useful insights into the correlation between the microstructure and mechanical properties of BMGs.

中文翻译：

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纳米压痕对金属玻璃退火速率敏感性的影响

通过纳米压痕研究了等温退火对Zr基块状金属玻璃（BMG）的应变速率敏感性（SRS）的影响。随着样品自由体积（FV）含量的减少，观察到了更阳性的SRS。此外，当FV退火时，SRS随着退火时间的增加而变得几乎恒定。通过考虑FV辅助的激活和剪切转变区（STZs）的组合，可以很好地理解其潜在机理。当前的工作可能会为BMG的微观结构和力学性能之间的相关性提供有用的见解。