Zr基块体金属玻璃蠕变行为的纳米压痕研究

Nanoindentation Investigation on Creep Behavior of Zr-Based Bulk Metallic Glass

摘要:

在本工作中，通过纳米压痕实验研究了加载速率和保载时间对(Zr0.6336Cu0.1452Ni0.1012Al0.12)97.4Er2.6块体金属玻璃（BMG）的蠕变变形行为的影响。实验结果表明，合金试样的蠕变位移随着加载速率或保载时间的增加而增大。另一方面，合金样品的硬度（H）也随着加载速率或保载时间的增加而降低。合金试样在纳米压痕过程中具有尺寸效应，合金试样的硬度随着压痕深度的增加而降低。合金试样在纳米压痕过程中具有锯齿流动现象，并且该现象具有速率依赖性。具体而言，随着加载速率的减小，锯齿流动现象更加明显。合金试样的蠕变应力指数随着加载速率或保载时间的增加而减小。

Abstract:

In the present work, the effect of loading rate and holding time on the creep deformation behavior of (Zr0.6336Cu0.1452Ni0.1012Al0.12)97.4Er2.6 bulk metallic glass (BMG) was investigated by using nanoindentation technique. Experimental results demonstrate that the creep displacement of specimen increases with the increase of loading rate or holding time. On the other hand, the hardness (H) of specimen falls with the rise of loading rate or holding time. The H drops with the growth of indentation depth during the nanoindentation process, which indicates that specimen has a size effect. Specimen has a serrated flow phenomenon which has rate dependence. Specifically, as the loading rate declines, the serrated flow phenomenon becomes more obvious. The creep stress exponent of specimen goes down with the increases of loading rate or holding time.