Impact of the plastic deformation microstructure in metals on the kinetics of recrystallization: A phase-field study
Impact of the plastic deformation microstructure in metals on the kinetics of recrystallization: A phase-field study
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金属塑性变形微观结构对再结晶动力学的影响：相场研究
DOI：
10.1016/j.actamat.2022.118332
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发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
El-Azab, Anter
中科院分区：
文献类型：
--
作者：
Hamed, Ahmed;Rayaprolu, Sreekar;Winther, Grethe;El-Azab, Anter
金属再结晶动力学对微观组织和变形历史的非均质性的敏感性是一个被广泛接受的实验事实。然而，现有的大多数再结晶模型要么采用平均场方法，要么采用晶界平均参数，从而忽略了先验变形引起的细观非均匀。在本研究中，我们用相场方法研究了形变诱导位错(亚晶)结构对金属再结晶动力学的影响。这里的主要焦点是位错晶胞边界的作用。相场模型的自由能公式通过将局域能量分配给由实验数据产生的位错微结构实现来解释微结构的非均质性。这些微结构的实现是使用几何上必要的和附带的位错边界的间距和错向角的普遍标度定律来创建的。所得到的自由能被用于基于Allen-Cahn的再结晶动力学模型，该模型用有限元方法求解。由此得到的解揭示了变形的空间非均匀性在再结晶核的非光滑生长中的关键作用以及最终的晶粒结构。结果表明，再结晶前沿的形态表现为凸起和回缩，这与实验结果一致。通过分解亚晶结构，该算法为开发完全考虑再结晶金属变形状态的预测动力学模型铺平了道路。
The sensitivity of recrystallization kinetics in metals to the heterogeneity of microstructure and deformation history is a widely accepted experimental fact. However, most of the available recrystallization models employ either a mean field approach or use grain-averaged parameters, and thus neglecting the mesoscopic heterogeneity induced by prior deformation. In the present study, we investigate the impact of deformation-induced dislocation (subgrain) structure on the kinetics of recrystallization in metals using the phase-field approach. The primary focus here is upon the role of dislocation cell boundaries. The free energy formulation of the phase-field model accounts for the heterogeneity of the microstructure by assigning localized energy to the resulting dislocation microstructure realizations generated from experimental data. These microstructure realizations are created using the universal scaling laws for the spacing and the misorientation angles of both the geometrically necessary and incidental dislocation boundaries. The resulting free energy is used into an Allen-Cahn based model of recrystallization kinetics, which are solved using the finite element method. The solutions thus obtained shed light on the critical role of the spatial heterogeneity of deformation in the non-smooth growth of recrystallization nuclei and on the final grain structure. The results showed that, in agreement with experiment, the morphology of recrystallization front exhibits protrusions and retrusions. By resolving the subgrain structure, the presented algorithm paves the way for developing predictive kinetic models that fully account for the deformed state of recrystallizing metals.