Modelling twinning evolution during plastic deformation in hexagonal close-packed metals
Modelling twinning evolution during plastic deformation in hexagonal close-packed metals
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DOI：
10.1016/j.matdes.2015.06.025
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发表时间：
2015-10
影响因子：
8.4
通讯作者：
E. Galindo-Nava
中科院分区：
文献类型：
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作者：
E. Galindo-Nava
提出了一个新的描述晶粒尺度和体积分数演化的模型。单个晶粒上的平均孪晶长度的演化方程表示在局部晶粒结构。这包括表征变形试样中的晶粒尺寸和取向分布。此外，孪晶体积分数预测计算集体孪晶体积增量对每个晶粒，如果晶粒结构是已知的。提出了一个孪晶成核率方程，它取决于位错活动，以及当地的孪晶和晶粒取向。该模型适用于描述在Be，Hf，Mg，Ti和Zr的各种加载和织构条件下的孪生行为，包括在MgY合金中的Y添加效果。孪晶演化进行了比较，在镁持有单峰和双峰晶粒尺寸分布。
A new model describing the twin size and volume fraction evolution at the grain level is proposed. An evolution equation for the mean twin length on individual grains is expressed in terms of the local grain structure. This includes characterising the grain size and orientation distributions in the deformed specimen. Additionally, the twin volume fraction is predicted by computing the collective twin volume increments on each grain, if the grain structure is known. A twin nucleation-rate equation is proposed; it depends on dislocation activity, and the local twin and grain orientations. The model is applied to describe twinning behaviour in Be, Hf, Mg, Ti and Zr for various loading and texture conditions, including Y addition effects in MgY alloys. Twinning evolution is compared in Mg holding unimodal and bimodal grain size distributions.