High-speed creep process mediated by rapid dislocation absorption in nanocrystalline Cu
High-speed creep process mediated by rapid dislocation absorption in nanocrystalline Cu
复制标题
纳米晶铜中快速位错吸收介导的高速蠕变过程
DOI：
10.1063/1.3694005
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发表时间：
2012-03
影响因子：
3.2
通讯作者：
Jiang, Qing
中科院分区：
文献类型：
--
作者：
Mu, Junwei;Jiang, Zhonghao;Zheng, Weitao;Tian, Hongwei;Lian, Jianshe;Jiang, Qing
在纳米压痕蠕变实验中，发现了由快速位错吸收引起的高速蠕变过程。蠕变应变和蠕变应变率强烈依赖于加载应变率，远高于Coble蠕变和热激活晶界滑移模型的预测值。我们的分析表明，晶界位错源可以被激活，在高加载应变率下可以有效地存储从晶界发出的位错，而在低加载应变率下则不能。观察到的高速蠕变过程主要是由储存位错的快速吸收和保温期内新形核的位错所致。我们的实验结果表明，纳米金属中的位错结构是高度不稳定的，位错活动可以在加载后继续进行，并导致显著的加载后塑性。
A high-speed creep process mediated by rapid dislocation absorption was found in the nanoindentation creep test on nanocrystalline Cu. The creep strain and creep strain rate depend strongly on the loading strain rate and are far higher than those predicted by the models of Coble creep and thermally activated grain boundary sliding. Our analysis revealed that grain boundary dislocation sources can be activated and emitted dislocations from grain boundaries can be stored effectively at a high loading strain rate, but cannot at a low loading strain rate. The observed high-speed creep process is mediated mainly by the rapid absorptions of the stored dislocations and the dislocations newly nucleated during the holding period. An implication of our experimental finding is that dislocation structure in nanocrystalline metals is highly unstable and dislocation activity can proceed after loading and lead to a significant post-loading plasticity.
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影响因子：
9.4
作者：
Yujie Wei;A. Bower;Huajian Gao
通讯作者：
Yujie Wei;A. Bower;Huajian Gao
应变率敏感性对纳米晶铜变形微观结构的依赖性
影响因子：
9.4
作者：
Huang, P.;Wang, F.;Lu, T. J.
通讯作者：
Lu, T. J.
影响因子：
56.9
作者：
Shan, ZW;Stach, EA;Mao, SX
通讯作者：
Mao, SX
影响因子：
9.4
作者：
B. Zhu;R. Asaro;P. Krysl;R. Bailey
通讯作者：
B. Zhu;R. Asaro;P. Krysl;R. Bailey
DOI：
10.1016/s0921-5093(02)00238-1
发表时间：
2003-01
影响因子：
6.4
作者：
H. Conrad
通讯作者：
H. Conrad