Effects of pre-compression deformation on nanoindentation response of Zr65Cu15Al10Ni10 bulk metallic glass
Effects of pre-compression deformation on nanoindentation response of Zr65Cu15Al10Ni10 bulk metallic glass
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DOI：
10.1016/j.jallcom.2016.03.057
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发表时间：
2016-07-25
影响因子：
6.2
通讯作者：
Yan, Jiwang
中科院分区：
文献类型：
--
作者：
Huang, Hu;Zhang, Jiliang;Yan, Jiwang
对具有预压缩变形（PCD）的Zr65Cu15Al10Ni10大块金属玻璃样品在不同条件下进行了纳米压痕实验。通过分析压痕硬度、残余形貌、堆积和锯齿状流动，比较研究了PCD对纳米压痕响应的影响。实验结果表明，当PCD为9 kN时，压痕硬度显著降低，即材料软化，而当PCD为18 kN和25 kN时，压痕硬度值与铸态试样的硬度值非常接近。此外，PCD还改变了大块金属玻璃的力学非均质性，即软硬区的分布。9 kN和18 kN PCD试样的残余形貌和荷载-位移曲线在宏观剪切带、堆积宽度、堆积高度和锯齿状流动等方面表现出相反的特征，表明纳米压痕过程中塑性流动存在差异。为了使这些现象合理化，讨论了剪切带和压残余应力之间的竞争机制。(C) 2016 Elsevier B.V.版权所有
Nanoindentation experiments were conducted on Zr65Cu15Al10Ni10 bulk metallic glass samples with pre-compression deformation (PCD) under various conditions. By analyzing indentation hardness, residual morphology, pile-up, and serrated flow, the effects of PCD on nanoindentation response were comparatively investigated. Experimental results indicate that 9 kN PCD induced remarkable decrease of indentation hardness, i.e. softening of the material, while for the 18 kN and 25 kN PCD samples, hardness values very close to that of the as cast sample were obtained. Furthermore, PCD also changed the mechanical heterogeneity, i.e., distribution of soft and hard regions in the bulk metallic glass. Residual morphologies and load-displacement curves of the 9 kN and 18 kN PCD samples showed opposite features in aspects of macroscopic shear bands, pile-up width, pile-up height, and serrated flows, suggesting different plastic flows during nanoindentation. To rationalize these phenomena, a competing mechanism between shear bands and compressive residual stress was discussed. (C) 2016 Elsevier B.V. All rights reserved.