Dependency of grain boundary dislocation network configuration on generalized stacking fault energy surface in FCC metals
Dependency of grain boundary dislocation network configuration on generalized stacking fault energy surface in FCC metals
复制标题
DOI：
10.1016/j.commatsci.2022.112003
复制
发表时间：
2023-02
影响因子：
3.3
通讯作者：
Yongxiang Li;Di Qiu;Yunzhi Wang
中科院分区：
文献类型：
--
作者：
Yongxiang Li;Di Qiu;Yunzhi Wang
我们使用微观相场（MPF）模型，结合广义堆垛层错能（GSFE）表面（即，以Ag、Cu、Rh、Ir、Pd和Pt六种不同GSFE表面的面心立方（FCC）金属为输入，系统研究了小角度纯扭转晶界位错网络组态的演化规律。通过能量最小化过程中晶体能和弹性应变能的相互作用，得到了GB位错网络的平衡构型。结果表明，对于{1 1 1}扭转晶界，虽然观察到了螺型几何必要位错，但根据上述金属系统的GSFE表面，它们可以是完全位错，也可以是部分位错。部分位错之间形成的堆垛层错区的面积定量表征为堆垛层错能的大小、弹性模量和GB取向差角的函数。直接基于材料性质和晶界取向差，建立了一个快速预测晶界位错网络几何特征的模型，并将其应用于具有相同晶界的另外两个金属系统（Au和Ni），验证了该模型的有效性。
We use a microscopic phase-field (MPF) model, incorporating the generalized stacking fault energy (GSFE) surfaces (i.e., theγ-surface) as inputs, to investigate systematically the evolution of dislocation network configurations at low-angle pure twist grain boundaries (GBs) in six face-centered cubic (FCC) metals (Ag, Cu, Rh, Ir, Pd and Pt) that have different GSFE surfaces. The equilibrium configurations of GB dislocation networks are obtained via the interplay between the crystalline energy and the elastic strain energy during the energy minimization process. It was found that for {1 1 1} twist GBs, though the geometrically necessary dislocations (GNDs) of the screw type are observed, they can be either full or partial ones depending on the GSFE surfaces of the above metal systems. The areas of the staking faults regions formed between partial dislocations are quantitatively characterized as a function of the magnitude of the stacking fault energy, the elastic modulus and the GB misorientation angle. A fast-acting model for predicting the geometric characteristics of the GB dislocation networks is developed based directly on the material properties and GB misorientation, which is validated by its applications to another two metal systems (Au and Ni) with the same GB.