Direct observation of individual dislocation interaction processes with grain boundaries.
Direct observation of individual dislocation interaction processes with grain boundaries.
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DOI：
10.1126/sciadv.1501926
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发表时间：
2016-11
期刊：
影响因子：
13.6
通讯作者：
Ikuhara Y
中科院分区：
文献类型：
--
作者：
Kondo S;Mitsuma T;Shibata N;Ikuhara Y
原位电子显微镜揭示了单个位错与晶界相互作用的动态过程。在变形过程中，晶界的存在对位错行为具有至关重要的影响；这些边界极大地改变了多晶材料的机械性能。人们认为晶界是位错滑移的有效障碍，但多年来这种类似障碍行为的起源一直是个猜想。通过透射电子显微镜内的原位纳米压痕实验，我们直接观察了 SrTiO3 中明确的高角度和低角度晶界如何阻碍单个位错的运动。我们的原位观察表明，大角度和小角度晶界都会阻碍位错滑移穿过它们，并且位错滑移的阻碍不仅仅源于几何效应；它也是由于晶界核心处的局部结构稳定效应而产生的，特别是对于小角度晶界。目前的研究结果表明，为了定量理解晶界处的位错阻碍过程，必须同时考虑几何效应和稳定效应。
In situ electron microscopy reveals the dynamic processes of individual dislocation interaction with grain boundaries. In deformation processes, the presence of grain boundaries has a crucial influence on dislocation behavior; these boundaries drastically change the mechanical properties of polycrystalline materials. It has been considered that grain boundaries act as effective barriers for dislocation glide, but the origin of this barrier-like behavior has been a matter of conjecture for many years. We directly observe how the motion of individual dislocations is impeded at well-defined high-angle and low-angle grain boundaries in SrTiO3, via in situ nanoindentation experiments inside a transmission electron microscope. Our in situ observations show that both the high-angle and low-angle grain boundaries impede dislocation glide across them and that the impediment of dislocation glide does not simply originate from the geometric effects; it arises as a result of the local structural stabilization effects at grain boundary cores as well, especially for low-angle grain boundaries. The present findings indicate that simultaneous consideration of both the geometric effects and the stabilization effects is necessary to quantitatively understand the dislocation impediment processes at grain boundaries.
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影响因子：
9.4
作者：
Brunner, Dieter
通讯作者：
Brunner, Dieter
影响因子：
1.6
作者：
CARTER, CB;HIRSCH, PB
通讯作者：
HIRSCH, PB
影响因子：
9.4
作者：
Hirel, P.;Mrovec, M.;Elsaesser, C.
通讯作者：
Elsaesser, C.
影响因子：
1.2
作者：
IKUHARA, Y;SUZUKI, T;KUBO, Y
通讯作者：
KUBO, Y
DOI：
10.1007/bf02661312
发表时间：
1972-01-01
期刊：
METALLURGICAL TRANSACTIONS
影响因子：
--
作者：
HIRTH, JP
通讯作者：
HIRTH, JP