A cluster-type grain interaction deformation texture model accounting for twinning-induced texture and strain-hardening evolution: Application to magnesium alloys
A cluster-type grain interaction deformation texture model accounting for twinning-induced texture and strain-hardening evolution: Application to magnesium alloys
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DOI：
10.1016/j.actamat.2013.12.007
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发表时间：
2014-04
期刊：
影响因子：
9.4
通讯作者：
Sijia Mu;Florian Tang;G. Gottstein
中科院分区：
文献类型：
--
作者：
Sijia Mu;Florian Tang;G. Gottstein
孪晶在形变织构演化中起着两个重要作用：孪晶使晶粒的孪晶体积不连续地重新取向，从而引起织构的变化;孪晶的片层结构减小位错滑移的平均自由程，有效地促进加工硬化。为了正确预测孪晶起重要作用的材料的织构演化，必须考虑变形孪晶的两种效应。在目前的工作中，这两种效果占在集群型变形织构晶粒相互作用（GIA）模型。采用单参数硬化模型考虑滑移诱导的应变硬化，该模型计算每个滑移系的流变应力演化。通过将孪晶层视为由孪晶畴和基体畴交替层形成的椭球形夹杂物，将孪晶诱导的应变硬化纳入模型。孪晶基体界面为后续滑移或进一步孪晶的传播提供了屏障并限定了定向平均自由程。改进后的GIA模型称为GIA-TW-HD模型。应用该模型预测了镁合金AZ 31在100 °C下的变形行为和织构演变。预测的织构演变以及应变硬化曲线与实验结果进行了比较。仿真结果与实验结果吻合较好。
Twinning plays two important roles in deformation texture evolution: it reorients the twinned volume of a grain discontinuously, thus causing a texture change; and the lamellar structure of twins reduces the mean free path for dislocation slip, which effectively promotes work-hardening. To correctly predict the texture evolution of materials in which twinning plays an important role, both effects of deformation twinning must be taken into consideration. In the current work, both effects are accounted for in the cluster-type deformation texture grain interaction (GIA) model. Slip-induced strain-hardening was considered by employing a one-parameter hardening model, which calculates the flow stress evolution for each slip system. Twinning-induced strain-hardening was incorporated into the model by treating twin lamellae as ellipsoidal inclusions formed by alternating layers of twin and matrix domains. The twin–matrix interfaces provide barriers and define a directional mean free path for the propagations of subsequent slip or further twinning. The modified GIA model is called the GIA-TW-HD model. It was applied to predict the deformation behavior and texture evolution of Mg alloy AZ31 at 100 °C. The predicted texture evolution as well as strain-hardening curves were compared with experimental results. Overall good agreement between simulation and experiment was obtained.