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本文基于微观相场模型模拟了Ni_(75)Al_xV_(25-x)(x=4.2,5.0)合金中DO_(22)(Ni_3V)到L1_2(Ni_3Al)相变过程.结合微观组织原子图像演化和界面处原子占位几率演化.研究了异相间有序畴界的结构及其迁移特征,提出了DO_(22)到L1_2相变过程的机制.研究表明,L1_2与DO_(22)相间存在5种界面,DO_(22)到L1_2相变过程中,除了界面(002)_D∥(001)_L之外,其他4种界面都可以迁移;在界面迁移过程中,界面(100)_D∥(200)_L和界面(100)_D∥(200)_L·1/2[001]在迁移前后,界面结构保持不变.而界面(002)_D∥(002)_L·1/2[100]迁移后形成界面(002)_D∥(002)_L,两者交替出现;相变过程中,界面迁移总是沿着最优化的路径进行原子跃迁和替换,遵循跃迁原子数目最少、跃迁路径最短原则.
In this paper, the phase transition of DO_ (22) (Ni_3V) to L1_2 (Ni_3Al) in Ni 75 Ga 2 x (25-x) x = 4.2,5.0 alloys was simulated based on the microscopic phase field model. The evolution of DOA (22) to L1_2 phase transition is proposed. The results show that there are five kinds of phase transitions between L1_2 and DO_ (22) Interface (00) _D // (001) _L, the other four kinds of interfaces can migrate during the process of phase transition from DO_ (22) to L1_2. During the process of interface migration, (100) _D // (200) _L · 1/2 [001] The interface structure remains unchanged before and after migration, and the interface (002) _D∥ (002) _L · 1/2 [100] Interface (002) _D // (002) _L, both of them appear alternately. In the process of phase transition, the interface migration always transforms and replaces the atom along the optimal path, following the principle of the least number of transitional atoms and the shortest transition path.