Non-Schmid behaviour during secondary twinning in a polycrystalline magnesium alloy
Non-Schmid behaviour during secondary twinning in a polycrystalline magnesium alloy
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DOI：
10.1016/j.actamat.2007.08.034
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发表时间：
2008-01-01
期刊：
影响因子：
9.4
通讯作者：
Ma, X.
中科院分区：
文献类型：
--
作者：
Barnett, M. R.;Keshavarz, Z.;Ma, X.
目前的工作结合电子背散射衍射和施密德分析来研究镁合金 Mg-3Al-1Zn 中的二次孪晶。检查父体和 {10 (1) over bar1}-{10 (1) over bar2} 双孪生体积之间的错误方向表明存在四种可能的变体。其中一种变体（与以 38 度 (12 10) 为特征的矩阵形成定向错误的变体）比其他变体更受青睐。这种变体涉及二次孪生系统的激活，与施密德型行为非常不一致。为了让次要双胞胎显着成长，它必须呈现出主要双胞胎所强制的形状。这对于应变兼容性来说不是最佳的。有人认为，38 度 12 10) 变体出现得最多，因为它提供了初级和次级孪晶面之间最接近的匹配，从而最大限度地减少了相容性应变。 (c) 2007 Acta Materialia Inc. 由 Elsevier Ltd 出版。保留所有权利。
The present work combines electron backscattering diffraction and Schmid analysis to investigate secondary twinning in the magnesium alloy Mg-3Al-1Zn. Inspection of the misorientations between the parent and {10 (1) over bar1}-{10 (1) over bar2} doubly twinned volumes reveals that there are four possible variants. One of these variants (the one that forms a misorientation with the matrix characterized by 38 degrees (12 10)) is favoured much more than the others. This variant involves the activation of secondary twinning systems quite inconsistent with Schmid-type behaviour. For the secondary twin to grow significantly it must take on a shape enforced by the primary twin. This is non-optimal for strain compatibility. It is argued that the 38 degrees 12 10) variant occurs most because it provides the closest match between the primary and secondary twinning planes, thus minimizing the compatibility strain. (c) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.