Size effect in bi-crystalline micropillars with a penetrable high angle grain boundary
Size effect in bi-crystalline micropillars with a penetrable high angle grain boundary
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DOI：
10.1016/j.actamat.2017.03.003
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发表时间：
2017-05
期刊：
影响因子：
9.4
通讯作者：
N. Malyar;J. Micha;G. Dehm;C. Kirchlechner
中科院分区：
文献类型：
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作者：
N. Malyar;J. Micha;G. Dehm;C. Kirchlechner
各种尺寸效应对晶界及其附近变形行为的影响尚未完全清楚。在这篇手稿中，通过一般的大角度晶界（HAGB）允许容易转移的滑移转移机制进行了研究，以了解尺寸依赖的位错晶界相互作用。在扫描电子显微镜和X-射线劳厄微衍射的铜单晶和双晶体的补充在situmicro压缩试验被用来与不断变化的微观结构的机械响应。结果表明，在晶界处没有位错堆积形成。缺乏堆积应力的结果在变形过程中，这是由初始位错源统计占主导地位。这通过单晶和双晶样品的相似尺寸标度证明，其中晶粒尺寸是特征长度标度。
The implications of various size effects on the deformation behavior of and near grain boundaries is not yet fully understood. In this manuscript, slip transfer mechanisms through a general high angle grain boundary (HAGB) allowing for easy transfer are investigated in order to understand the size dependence of the dislocation-grain-boundary interaction. Complementaryin situmicro compression tests on copper single and bi-crystals in the scanning electron microscope and with x-ray Laue microdiffraction were used to correlate the mechanical response with the evolving microstructure. It is shown that no dislocation pile-up is formed at the boundary. The lack of pile-up stresses results in a deformation process which is dominated by the initial dislocation source statistics. This is evidenced by similar size scaling of the single and bi-crystalline samples with the grain size being the characteristic length scale.