Shear banding in commercial pure titanium deformed by dynamic compression
Shear banding in commercial pure titanium deformed by dynamic compression
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动态压缩变形的商用纯钛中的剪切带
DOI：
10.1016/j.actamat.2014.07.011
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发表时间：
2014-10-15
期刊：
影响因子：
9.4
通讯作者：
Wang, J. T.
中科院分区：
文献类型：
--
作者：
Sun, J. L.;Trimby, P. W.;Wang, J. T.
通过动态压缩对圆柱形密排六方钛试样进行预变形，在试样的不同部位产生粗晶和超细晶组织，然后进一步动态压缩直至失效，从而研究了材料中储存应变和晶界能对剪切带的影响。在最终压缩过程中形成的长剪切带穿过样品的完整对角线。利用电子背散射衍射系统地研究了剪切带引起的结构演化。结果表明，基体中的原始储能在变形诱导晶粒细化和晶粒长大的竞争中起着重要作用，并决定了剪切带中最终的平均晶粒尺寸。剪切带导致晶粒重取向，使得大多数晶粒中的一个紧密堆积的<11（2）在棒0上>方向和一个<10（1）在棒0上>方向分别平行于局部剪切方向和局部剪切面的法线方向。剪切带中的晶粒取向有利于棱柱< a >滑移，而基体中的织构是稳定的压缩织构，有利于基底< a >滑移。研究结果推进了我们对非均匀变形条件下剪切带行为的理解，也促进了动态压缩下材料的整体力学行为。(C)2014 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
A cylindrical hexagonal-close-packed Ti sample was pre-deformed by dynamic compression to produce coarse-grained and ultrafine-grained structures in different parts of the sample followed by further dynamic compression to failure, making it possible to explore the effect of stored strain and grain boundary energy on shear banding in the material. A long shear band that formed during the final compression process passed through a complete diagonal of the sample. Electron backscattered diffraction was used to systematically investigate the shear-banding-induced structural evolution. Results show that the original stored energy in the matrix plays a significant role in the competition between deformation-induced grain refinement and grain growth, which determines the final average grain size in a shear band. Shear banding leads to grain reorientation such that one close-packed < 1 1 (2) over bar 0 > direction and one < 1 0 (1) over bar 0 > direction in most grains are parallel to the local shear direction and the normal direction to the local shear plane, respectively. The grain orientation in the shear band favours prismatic < a > slip, while the texture in the matrix, which is a stable compression texture, benefits the basal < a > slip. The results advance our understanding of the shear banding behaviour in heterogeneous deformation conditions and also the overall mechanical behaviour of materials under dynamic compression. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.