铝合金应变诱导晶粒异常长大行为的晶体塑性-相场法耦合模拟（英文）

提出一种预测变形铝合金在退火过程中应变诱导晶粒异常长大行为的介观耦合建模方法。基于晶体塑性有限元法(CPFE)计算塑性变形中的位错密度和变形储能分布；以储能和局部界面曲率为晶界迁移驱动力，建立基于连续场法的改进相场(PF)模型，并采用插值法将CPFE计算结果向PF模型进行映射，实现CPFE-PF的耦合模拟。采用理想双晶组织模拟初步校准PF模型，然后将该CPFE-PF耦合模型应用于变形AA3102铝合金退火过程的多晶组织演化模拟，进一步验证模型有效性。结果表明，退火时变形基体中的低储能形核点优先长大；而当变形量在临界塑性应变附近时，由于结晶形核数量的有限性和储能分布的不均匀性，将产生晶粒异常长大现象。

Simulation of strain induced abnormal grain growth in aluminum alloy by coupling crystal plasticity and phase field methods

A mesoscale modeling methodology is proposed to predict the strain induced abnormal grain growth in the annealing process of deformed aluminum alloys. Firstly, crystal plasticity finite element (CPFE) analysis is performed to calculate dislocation density and stored deformation energy distribution during the plastic deformation. A modified phase field (PF) model is then established by extending the continuum field method to consider both stored energy and local interface curvature as driving forces of grain boundary migration. An interpolation mapping approach is adopted to transfer the stored energy distribution from CPFE to PF efficiently. This modified PF model is implemented to a hypothetical bicrystal firstly for verification and then the coupled CPFE-PF framework is further applied to simulating the 2D synthetic polycrystalline microstructure evolution in annealing process of deformed AA3102 aluminum alloy. Results show that the nuclei with low stored energy embedded within deformed matrix tend to grow up, and abnormal large grains occur when the deformation is close to the critical plastic strain, attributing to the limited number of recrystallized nuclei and inhomogeneity of the stored energy.