Ni_(75)Al_(6.5)V_(18.5)合金沉淀过程界面演化的微观相场模拟  

Interfacial Evolution of Ni_(75)Al_(6.5)V_(18.5) Alloy During Precipitation Process with Microscopic Phase Field Simulation

作　　者：赵宇辉[1] 王丽芬[1] 刘杰[1] 侯华[2] 

机构地区：[1]河北工业职业技术学院机电工程系 [2]中北大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2016年第3期237-241,共5页Special Casting & Nonferrous Alloys

基　　金：河北工业职业技术学院自然科学研究课题资助项目(YZ-1306)

摘　　要：采用微观相场动力学模型,模拟了Ni_(75)Al_(6.5)V_(18.5)合金的早期沉淀过程。通过分析原子演化图像、原子的占位几率,探讨了沉淀机制及一些非平衡现象。结果表明,可迁移界面均具有特定的原子跃迁模式,且原子跃迁呈现一定的规律。其中,异相界面(100)D∥(200)L和(100)D∥(200)L·1/2[001]在迁移前后,均保持原来的界面结构不变,而(200)D∥(100)L·1/2[100]迁移后形成(200)D∥(100)L,且这两种界面交替出现;L12相向DO22相的转变是异相界面迁移诱导的过程:两相界面处的Ni原子选择最优路径跃迁至最近邻的Al格点上,V原子则迁移向DO22畴内部,Al则向外迁移至两相界面处。异相界面迁移以原子跃迁和替换模式进行,遵循阻力最小和行程最短的规律,即L12相向DO22相的转变过程表现出热力学和动力学最优化的特点。Microscopic phase-field model was used to simulate the early precipitation process of Ni75Al6.5V18.5alloy.By analyzing the evolution of atomic image and the atomic occupation probability,the precipitation mechanism and some non-equilibrium phenomena were systematically explored.The result show that transferable interface has a specific atomic transition mode,and the atomic transition presents to some regularity.（100）D∥（200）Land（100）D∥（200）L·1/2[001]before and after the migration,interface structure remains unchanged,and（200）D∥（100）L·1/2[100]is migrated to form（200）D∥（100）L,alternating between the two.Phase interface migration can induce phase transition L12 to DO22,and Ni atoms at the interface are stepped to the position of the nearest neighbor of Al,and V is migrated to the DO22 domain,while Al is migrated to the outside interface.Interphase interface migration comes by the atomic transition and replacement model,following the shortest path of least resistance and replace mode atomic transition,which means the transformation of L12 phase to DO22 phase mutually following the best thermodynamics and kinetics optimization path.

关 键 词：微观相场 占位几率 界面迁移 异相界面 

分 类 号：TG146.15[一般工业技术—材料科学与工程]