Ni-Al-V合金有序畴界面结构的微观相场模拟

Computer Simulation of Ordered Interphase Boundary Structure of Ni-Al-V Alloy Using Microscopic Phase-Field Method

利用微观相场动力学模型模拟了Ni-Al-V合金沉淀有序相之间界面的微结构及其演化过程。研究结果表明,L12相之间形成3种类型的畴界结构,界面宽度较小,其中一种界面处Al原子占位几率基本达平衡值。D022相根据投影后[10]和[01]两个不同取向的结合,形成8种类型的畴界结构,相同取向的畴界较宽,不同取向的畴界处V原子占位几率较高。两种不同有序相形成4种类型畴界,由于后析出相在先析出相的界面形核长大,界面处相应原子占位几率达平衡值,两相界面处连续过渡。D022有序相[01]方向形成的界面随沉淀过程进行,由无序变为有序窄界面,之后界面处又发生分解成为无序相。

The microscopic structure and evolution of ordered interphase boundary of Ni-Al-V alloy was investigated using microscopic phase-field model. The results show that three kinds of interphase boundaries are formed between LI2 phases, the width of the interphase boundaries are narrower, and of which one kind of interphase boundary is in equilibrium for the occupation probability of Al atoms. According to the different orientation variants of [ 10] and [01 ] of the projection of D022, there form eight kinds of interphase boundaries structure, in which the interphase boundaries are wider with the same orientation variants, and the occupation probability of V atoms reach the equilibrium value with different orientation variants. There are four kinds of interphase boundaries between the different phases. The occupation probability of atoms in the interphase boundaries reach the equilibrium value and two phase transit continuously, for one phase precipitate from the interphase boundary of another. With the precipitation process, the interphase boundaries formed in [01] direction of D022 transform from disordered to ordered and become narrower firstly and then dissolve into disordered phase.