Phase-field modeling of grain growth in presence of grain boundary diffusion and segregation in ceramic matrix mini-composites
Phase-field modeling of grain growth in presence of grain boundary diffusion and segregation in ceramic matrix mini-composites
复制标题
DOI：
10.1016/j.commatsci.2021.110295
复制
发表时间：
2021-04
影响因子：
3.3
通讯作者：
J. Kundin;Hedieh Farhandi;Kamatchi Priya Ganesan;Renato S. M. Almeida;K. Tushtev;K. Rezwan
中科院分区：
文献类型：
--
作者：
J. Kundin;Hedieh Farhandi;Kamatchi Priya Ganesan;Renato S. M. Almeida;K. Tushtev;K. Rezwan
晶界扩散和偏析会影响晶粒生长动力学、晶粒尺寸分布，从而影响陶瓷基复合材料的机械性能。本文提出了一种相场建模方法，用于模拟在高于 1000 °C 的温度下，在存在掺杂剂从基体到纤维的晶界扩散（反之亦然）的情况下，嵌入氧化铝基体中的多晶氧化铝纤维的晶粒生长。晶粒生长的多相场模型[I。 Steinbach 和 F. Pezzolla，物理学家。 D, 134 (1999) 385] 通过结合晶界扩散、晶界偏析模型以及界面迁移率对偏析浓度的依赖性进行了扩展。通过与实验测量值的比较，估计了描述真实微观结构演化的模型动力学参数。Nextel 610 光纤中掺杂剂扩散引起的晶粒生长的模拟和实验结果表明，晶界扩散对晶粒尺寸分布的显着影响。利用数值试验的结果，通过不同温度下的实验数据，通过反演的方法来调整晶界扩散系数的值。根据模拟，Mg 的扩散系数估计比 Si 的扩散系数高 6-7 倍。
The grain boundary diffusion and segregation can influence the grain growth kinetics, the grain size distribution, and therefore the mechanical properties of the ceramic matrix composites. The present paper proposes a phase-field modeling approach to simulate the grain growth in polycrystalline alumina fibers embedded in alumina matrix at temperatures above 1000 °C in presence of the grain boundary diffusion of dopants from the matrix to the fiber and vice versa. The multi-phase-field model for grain growth [I. Steinbach and F. Pezzolla, Phys. D, 134 (1999) 385] is extended by the incorporation of the grain boundary diffusion, grain boundary segregation model, and the dependence of the interface mobility on the segregation concentration. The kinetic parameters of the model which allow describing the real microstructure evolution were estimated by the comparison to the experimental measurements.The simulation and experimental results of the grain growth with the diffusion of dopants in Nextel 610 fibers show the significant effect of the grain boundary diffusion on the grain size distribution. The results of numerical tests were used to adjust the values of the grain boundary diffusion coefficients by the experimental data at different temperatures by means of an inverse method. From the simulations, the diffusion coefficient of Mg was estimated to be 6–7 times higher than that of Si.