A criterion of the critical threshold of the maximum shear stress in bulk metallic glasses with cryogenic thermal cycling by statistics in nanoindentation
A criterion of the critical threshold of the maximum shear stress in bulk metallic glasses with cryogenic thermal cycling by statistics in nanoindentation
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DOI：
10.1016/j.msea.2023.145031
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发表时间：
2023-04
期刊：
影响因子：
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通讯作者：
H. Zhang;Zhong Wang;P. Liaw;Junwei Qiao
中科院分区：
文献类型：
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作者：
H. Zhang;Zhong Wang;P. Liaw;Junwei Qiao
金属玻璃的剪切转变区已被广泛地用纳米压痕法研究。着重分析了相关参数之间的数学关系。通过低温热循环处理，获得了不同激活体积的大块非晶合金。纳米压痕实验在载荷控制加载模式下进行。通过降噪处理和统计分析，得到了最大剪应力的临界阈值（τ max）C。通过引入一阶多项式，由非线性斜率得到活化体积V*。基于平均场理论，成功地建立了一个判据，（τ max）C= V*− λ，其中λ= 0.30±0.10。根据对金属玻璃（τ max）C和V* 的大量研究，提出了该判据的三个适用条件。
The shear transformation zones of metallic glasses have been widely studied by nanoindentation. In this work, the mathematic relationship between the relevant parameters is analyzed emphatically. Bulk metallic glasses were given different activation volumes by the cryogenic thermal cycling treatment. Nanoindentation experiments were carried out in a load-controlled loading mode. The critical threshold of the maximum shear stress,(τ max) C, was obtained by the noise-reduction procedures and the statistical analysis. And the activation volume, V*, was obtained from the nonlinear slope by introducing a first-order polynomial. Based on the mean-filed theory, a criterion is successfully established,(τ max) C= V*− λ, where λ= 0.30±0.10. According to lots of previous studies on (τ max) C and V* of metallic glasses, three applicable conditions of the criterion are extracted.