Ni-Al-V合金中异相界面成分及其演化的微观相场模拟

Microscopic Phase Field Simulation on the Solute Segregation and Composition Evolution of Heterointerfaces in Ni-Al-V Alloy

摘要:

基于微观相场模型模拟Ni-Al-V合金沉淀过程，研究合金中有序无序界面和异相间有序畴界的成分及其演化。研究表明，合金元素的偏聚和贫化与界面类型有关。在DO22相与无序相间的有序无序界面处，Ni和Al偏聚，V贫化；在L12相与无序相间的有序无序界面处，Ni和Al贫化，V偏聚；在异相间有序畴界处，V在界面的DO22相一侧贫化，在界面的L12相一侧偏聚；Al则在界面的DO22相一侧偏聚，在界面的L12相一侧贫化。Ni的成分分布与界面的形成方式有关。随着时间的进行，界面处合金元素的成分分布变得更加明锐，但合金元素的偏聚和贫化倾向不变

Abstract:

Based on the microscopic phase field model, the precipitation process of Ni-Al-V alloy was simulated. The composition distribution and the evolution of order-disordering interface and ordered heterointerface formed between DO22 and L12 phase were studied. The results show that the degree and the preference of segregation or the depletion of alloying elements are related with the atomic structure of interfaces. Ni and Al segregate, V depletes at the order-disorder interface formed between DO22 and disorder phases. Ni and Al deplete, V segregates at the order-disorder interface formed between L12 and disorder phases. At the ordered heterointerfaces, V segregates at the DO22 side of the interface but depletes at the L12 side of the interface, Al depletes at the DO22 side of the interface but segregates at the L12 side of the interface. The distribution of Ni at the ordered heterointerface is related with the formation process of the interface. The preferences of segregation or the depletion of alloy elements remain unchanged, but the distribution of alloy elements becomes sharp during the evolution of interface