On the intrusion-like co-zone twin-twin structure: an in situ observation
On the intrusion-like co-zone twin-twin structure: an in situ observation
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类侵入共区孪生结构：原位观察
DOI：
10.1016/j.matlet.2020.129140
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发表时间：
2021
影响因子：
3
通讯作者：
Jiang, Y.
中科院分区：
文献类型：
--
作者：
Culbertson, D.;Yu, Q.;Jiang, Y.
在沿轴单调张力作用下，对原始单晶镁试样进行了原位电镜和原位电子背散射衍射测试。在微米尺度上首次观察到侵入状共带孪晶结构。现场观测表明，侵入状双孪结构由多个双孪晶界（TTBs）和非相干双孪晶界（I-CTBs）组成。初始相互作用产生撞击式TTBA和锐角TTBA。在钝角侧的局部结区，由于首选的局部孪晶剪应力，碰撞孪晶位错（TDs）在TTBI附近进一步沉积，导致TTBI附近的碰撞孪晶边界曲线不相干。不久之后，钝角侧的势垒孪晶界迁移并包围非相干碰撞孪晶界。序列TTBI、TTBA和在钝角侧局部形成的I-CTBs的组合形成了微米尺度下侵入状孪晶结构的最终形态。
Anin situoptical microscopy combined withex situelectron backscatter diffraction testing was applied to a pristine single-crystal magnesium specimen under monotonic tension along thec-axis. An intrusion-like co-zone twin-twin structure is observed for the first time at the micron scale.In situobservation reveals that the intrusion-like twin-twin structure consists of multiple twin-twin boundaries (TTBs) and incoherent twin boundaries (I-CTBs) following energetically favorable formation sequences. The initial interaction results in the impinging TTBIand the acute-angle TTBA. In the local junction region on the obtuse angle side, the impinging twinning dislocations (TDs) further deposit near TTBIdue to the preferred local twinning shear stress, leading to the incoherent curve of the impinging twin boundary adjacent to TTBI. Shortly after, the barrier twin boundary on the obtuse angle side migrates and encompasses the incoherent impinging twin boundary. The combination of sequential TTBI,TTBA, and I-CTBs formed locally on the obtuse angle side shapes the final configuration of the intrusion-like twin-twin structure at the micron scale.