中文摘要：

有低艾尔内容的 Ni-Cr-Al 合金的降水过程基于显微镜的阶段地在原子规模被学习结合的运动模型有弹性的紧张精力。目的是在降水机制和合金的词法进化上调查有弹性的紧张精力的效果。模拟结果证明在降水的早阶段， D0_(22 ) 阶段和 L1_2 阶段介绍不规则的形状，并且他们随机在矩阵散布。与老化的进步， L1_2 阶段和 D0_(22 ) 分阶段执行变化进适合形状和他们的取向变得更明显。在以后的阶段， L1_2 阶段和 D0_(22 ) 分阶段执行现在适合与圆角落塑造并且排列[100 ] 并且[010 ] 方向，和高度优先的选择微观结构被形成。在 Ni-17%Cr-7.5%Al (莫耳分率) 合金的 L1_2 阶段的早降水的机制是非古典的成核生长 andspinodal 分解的混合风格， D0_(22 ) 阶段是 spinodal 分解。阶段和 D0_(22 ) 在尼克尔·艾尔合金分阶段执行的 L1_2 的早降水的机制是 non-classicalnucleation 和生长。变粗的过程遵循规则优先变粗选择。

英文摘要：

The precipitation process of Ni-Cr-Al alloy with low Al content was studied at atomic scale based on the microscopic phase-field kinetic model coupled with elastic strain energy. The aim is to investigate the effect of elastic strain energy on precipitation mechanism and morphological evolution of the alloy. The simulation results show that in the early stage of precipitation, D022 phase and Ll2 phase present irregular shape, and they randomly distribute in the matrix. With the progress of aging, Ll2 phase and D022 phase change into the quadrate shape and their orientations become more obvious. In the later stage, Ll2 phase and D022 phase present quadrate shape with round corner and align along the [100] and [010] directions, and highly preferential selected microstructure is formed. The mechanism of early precipitation of Ll2 phase in Ni-17%Cr-7.5%Al （mole fraction） alloy is the nfixed style of non-classical nucleation growth and spinodal decomposition and the D022 phase is the spinodal decomposition. The mechanisms of early precipitation of L 12 phase and D022 phase in Ni-12.5%Cr-7.5% Al alloy are both the non-classical nucleation and growth. The coarsening process follows the rule of preferential selected coarsening.