[P1-62] Investigation of abnormal grain growth conditions by phase-field method
To improve the properties of materials by controlling their textures and grain sizes, it is essential to accurately predict abnormal grain growth, a phenomenon through which a few grains undergo preferential growth. In addition, the abnormal grain growth is considered to be one of the origins for the nucleation of recrystallized grains and, thus, is of great importance for modelling recrystallization processes.
As a prominent theory of abnormal grain growth, that proposed by Humphreys (here referred to as the cellular microstructural stability (CMS) theory) is well known. In this theory, a complicated polycrystalline microstructure, where grain size, boundary energy, and boundary mobility are not uniform, is simplified as a cellular microstructure model. The model consists of two ingredients: a specific grain and its surrounding matrix with uniform grain size and boundary properties. This modelling makes it possible to describe the abnormal grain growth behavior of the specific grain using only three parameters, i.e., its relative size, boundary energy, and boundary mobility normalized by those of the matrix. However, the validity of this theory has not been confirmed yet neither in experiment and simulation.
In this study, we aim to evaluate the applicable range of the CMS theory via systematic two-dimensional numerical simulations. As the numerical model, the multi-phase-field model [2] is employed, enabling accurate treatment of curvature-driven grain boundary migration in polycrystalline systems. Grain growth simulations are performed while varying the size, boundary energy, and boundary mobility of a specific grain in the matrix. By comparing the simulated results with the prediction of the CMS theory, we reveal the validity and applicable range of the theory.
[1] F. J. Humphreys, Acta Mater., 45, (1997), 4231.
[2] I. Steinbach, F. Pezzolla, Physica D, 134, (1999), 385.
As a prominent theory of abnormal grain growth, that proposed by Humphreys (here referred to as the cellular microstructural stability (CMS) theory) is well known. In this theory, a complicated polycrystalline microstructure, where grain size, boundary energy, and boundary mobility are not uniform, is simplified as a cellular microstructure model. The model consists of two ingredients: a specific grain and its surrounding matrix with uniform grain size and boundary properties. This modelling makes it possible to describe the abnormal grain growth behavior of the specific grain using only three parameters, i.e., its relative size, boundary energy, and boundary mobility normalized by those of the matrix. However, the validity of this theory has not been confirmed yet neither in experiment and simulation.
In this study, we aim to evaluate the applicable range of the CMS theory via systematic two-dimensional numerical simulations. As the numerical model, the multi-phase-field model [2] is employed, enabling accurate treatment of curvature-driven grain boundary migration in polycrystalline systems. Grain growth simulations are performed while varying the size, boundary energy, and boundary mobility of a specific grain in the matrix. By comparing the simulated results with the prediction of the CMS theory, we reveal the validity and applicable range of the theory.
[1] F. J. Humphreys, Acta Mater., 45, (1997), 4231.
[2] I. Steinbach, F. Pezzolla, Physica D, 134, (1999), 385.