Phase Field Simulation of Effect of Grain Boundary Diffusion on α Phase Dissolution [晶界扩散对Ti-6Al-4V中α相溶解影响的相场模拟]

作者：Liu T.; Yang M.^*; Wang G.; Wang L.; Xu D.

来源：Rare Metal Materials and Engineering, 2019, 48(9): 2864-2872.

• Dissolution
• Grain boundary diffusion
• Phase field model
• Phase size distribution
• The spatial distribution of phase

In order to study the phase transformations in consideration of the grain boundary diffusion, the diffusion along grain boundary was incorporated in the quantitative phase field model coupled with the Kim-Kim-Suzuki (KKS). The effect of the number of grain boundaries, the spatial distribution and size distribution (PSD) of α phase on the α phase dissolution was researched. The results show that grain boundaries are a faster element diffusive path. The larger the number of grain boundaries is, the faster the kinetics of α phase dissolution is. Namely, the kinetics of α phase dissolution is fastest when the phase is located at triple junctions. However, the dissolution kinetics is of little difference when α phase is on the grain boundary and distributed uniformly in the matrix. Compared to the phase dissolution rate in two-dimensional condition, the effect of the grain boundary diffusion on dissolution kinetics is more obvious in three-dimensional condition. When phase transformation is dominated by bulk diffusion of solute, the spatial distribution of α phase is a main factor affecting the α phase dissolution. But when phase transformation is dominated by grain boundary diffusion of solute, the effects of other size distributions on the dissolution of α phase are not obvious except for uniform PSD.

• 单位
  华南理工大学