The externally applied stress was introduced to the microscopic phase field model to study the directional coarsening behaviors of the aging precipitate L12 and D022 of Ni75 Al11.5 V13.5 alloy at 1 046.5 K. The results show that the microscopic phase field model could be used to discover the phase structure, the atom configuration of crystal and the interface between ordered phase precipitate particles. The magnitude,direction and duration of the externally applied stress may obviously influence the aging behavior of the L12 phase. The larger the applied stress and the longer the duration are used, the more obvious the directional coarsening effects become. The D022 phase nucleates along the interface between the L12 phase and the matrix and grows within the spaces among the L12 precipitates. Thus the morphology of D022 phase is always constrained by the L12 phase.%为研究镍基合金Ni75 Al11．5 V13．5等温时效沉淀颗粒在外应力场作用下的长大，在三元微观相场模型中引入外加应力场，模拟1046．5 K时效产物L12和D022在外加应力作用下的定向粗化．计算结果表明，微观相场模型可以模拟相结构和晶格中的原子配置，并能清晰地模拟有序相沉淀颗粒间界面．外加应力大小和方向以及持续施加的时间对L12沉淀时效行为有显著影响，施加的外加应力越大、持续时间越长，外加应力方向的定向粗化效应越明显．时效过程中，D022相在L12相与母相界面形核且D022相L12相的间隙中生长，其形态始终受L12相的制约．
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