摘要
通过纳米压痕蠕变实验研究了加载速率对{[(Fe0.6Co0.4)0.75B0.2Si0.05]0.96Nb0.04}96Cr4块体金属玻璃室温蠕变变形的影响。结果表明,该铁基块体金属玻璃的蠕变变形随着加载速率的增加而增大。此外,根据经验幂率函数计算得到了材料室温蠕变应力指数,当加载速率从1mN/s增加到50mN/s时,应力指数从28.1逐渐下降到4.9,显示出显著的压痕加载速率敏感性。最后,基于自由体积理论和剪切转变区理论对该铁基块体金属玻璃的纳米压痕蠕变行为进行了探讨,并对实验结果和分析结果提供了半定量的解释。
Effect of loading rate on room temperature creep deformation of {[(Fe0.6Co0.4)0.75B0.2Si0.05]0.96Nb0.04}96Cr4 bulk metallic glass (BMG) was investigated by performing nanoindentation creep experiments. Experimental results show that the creep displacement of the Fe-based BMG increases with increasing the loading rate. Furthermore, based on an empirical power-law equation, the stress exponent for room temperature creep of this BMG was calculated. As the indentation loading rate increases from 1 mN/s to 50 mN/s, the stress exponent decreases gradually from 28.1 down to 4.9, exhibiting significant indentation loading rate sensitivity. Finally, nanoindentation creep behavior in this Fe-based BMG was demonstrated in terms of free volume and “shear transformation zone” (STZ) theories, which could provide semi-quantitative explanation as for the observed experimental and analytical results.
出处
《中国有色金属学会会刊：英文版》
CSCD
2013年第6期1646-1651,共6页
Transactions of Nonferrous Metals Society of China
基金
Project(51071134)supported by National Natural Science Foundation of China
Project(2012WK2008)supported by the Planned Science and Technology Project of Hunan Province,China
Project(09A088)supported by Scientific Research Fund of Hunan Provincial Education Department,China
Project(12JJ2024)supported by Provincial Natural Science Foundation of Hunan,China
Project(2011XZX18)supported by Xiangtan University Natural Science Foundation,China
