Mesoscale Modeling of Dynamic Recrystallization: Multilevel Cellular Automaton Simulation Framework
Mesoscale Modeling of Dynamic Recrystallization: Multilevel Cellular Automaton Simulation Framework
复制标题
动态重结晶的介观建模：多级元胞自动机仿真框架
DOI：
10.1007/s11661-019-05620-3
复制
发表时间：
2020-03-01
影响因子：
2.8
通讯作者：
Cui, Zhenshan
中科院分区：
文献类型：
--
作者：
Chen, Fei;Zhu, Huajia;Cui, Zhenshan
元胞自动机(CA)方法在计算材料科学中的主要应用，不仅在于不需要复杂的微分方程组计算就能模拟再结晶过程，而且还能直观地显示不连续再结晶过程中的形核和晶粒长大。将多层元胞空间的思想融入到经典元胞自动机仿真框架中，制定了元胞状态转换规则和不同元胞空间之间的数据传输规则，首次建立了动态再结晶的多层元胞自动机模型。MCA模型包括多层再结晶形核(MRN)模块和全场多层晶粒拓扑形变(FMGTD)模块。对316LN不锈钢进行了热压缩实验，并将所建立的MCA模型应用于316LN钢的DRX数值模拟。通过将仿真结果与实验结果进行对比，验证了该模型的准确性和可靠性。讨论了FMGTD模块中的层数N和离散应变增量等模拟参数对模拟结果的影响。MCA模型中的离散细胞空间面积(即颗粒拓扑映射精度)随N增大而增大，但随离散应变的增大而减小。结果表明，改进的MCA模型不仅能更准确地描述再结晶形核过程中的晶粒拓扑变形，而且更符合再结晶形核的物理机制。MCA模型的计算精度高于现有的CA模型。此外，MCA模型在保证较高的晶粒拓扑映射精度的同时，能够更接近真实的变形过程，解决了现有CA模型中晶界面积损失的问题。
The main attraction of cellular automaton (CA) method used in computational material science lies on not only the simulation of recrystallization without the complicated differential equations calculation, but also the visualization of nucleation and grain growth during discontinuous recrystallization. In this work, by incorporating the idea of multilevel cellular space into the classical CA simulation framework and formulating cellular state transformation rules and data transfer rules between different levels of cellular space, the multilevel cellular automaton (MCA) model for dynamic recrystallization (DRX) is constructed for the first time. The developed MCA model includes a multilevel recrystallized nucleation (MRN) module and a full-field multilevel grain topological deformation (FMGTD) module. The thermal compression experiments of 316LN stainless steel are carried out, and the developed MCA model is applied to the numerical simulation of DRX for 316LN steel. The accuracy and reliability of this model are verified by comparing simulation results with experimental results. The influences of simulation parameters such as the number of levelsNin the FMGTD module and the discrete strain increment on simulation results are discussed. The discrete cellular space area (i.e., grain topology mapping accuracy) in the MCA model increases withNbut decreases with the discrete strain increment. The results show that the developed MCA model can not only describe the grain topological deformation in the DRX process more accurately but also more compatible with the physical mechanism of recrystallized nucleation. The calculation accuracy of the MCA model is higher than the existing CA model. Besides, the MCA model can be closer to the real deformation process while ensuring the high grain topology mapping accuracy and solve the problem of the loss of grain boundary area in the existing CA model.