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采用微观弹性相场动力学模型,研究由共格错配产生的弹性畸变能对Ni-Al合金沉淀过程中γ′(Ni3Al)相有序化过程的影响。模拟结果表明,对于不同的沉淀机制,如非经典形核、非经典形核与失稳分解的混合机制及失稳有序化,弹性畸变能均阻碍Al原子在β格点的占位,从而阻碍有序化过程的进行。同一时间步长下,考虑弹性畸变能的合金,其γ′相内浓度和长程序参数曲线的高度和宽度均小于忽略弹性畸变能的合金,曲线分布更加弥散。弹性畸变能改变了γ′相的空间排列及微观形貌,最终形成沿弹性“软方向”择优排列的共格微观组织。
The microscopic elastic phase field dynamics model was used to study the effect of elastic distortions caused by the coherent mismatch on the ordering of γ ’(Ni3Al) phase during the precipitation of Ni-Al alloy. The simulation results show that for different precipitation mechanisms, such as non-classical nucleation, mixing mechanism of non-classical nucleation and instability decomposition, instability ordering and elastic distortion, they all obstruct the occupancy of Al atoms in the β lattice. Hinder the process of ordering. At the same time step, considering the alloy with elastic distortion energy, the height and width of γ ’phase concentration and long parameter curve are less than that of alloy with elastic distortion energy, and the curve distribution is more diffuse. The elastic distortion can change the spatial arrangement and the micro-morphology of the γ ’phase and finally form a coherent microstructure that is preferentially arranged along the elastic “soft direction”.