Ni-Mo四近邻作用能对Ni75Al14Mo11合金沉淀行为影响的微观相场

基于微观扩散方程,采用微观离散格点相场法研究Ni-Mo原子间四近邻相互作用能对Ni75Al14Mo11合金沉淀过程微观机制的影响。通过原子尺度的结构演化图、表征浓度和有序度的成分序参数和长程序参数分析沉淀相的有序化、簇聚、镍原子反向析出及粗化行为等。研究结果表明:最近邻、第三近邻原子间作用能增大,可促进沉淀相的簇聚及有序化,但抑制后期镍基原子团簇的反向析出及粗化;次近邻、第四近邻原子间作用能增大的影响则与之相反;在相同条件下,外层作用能对沉淀相的有序化和簇聚影响最大。

Microscopic phase-field simulation for influence of Ni-Mo fourth-nearest interaction energy on precipitation process of Ni75Al14Mo11 alloy

The influence of Ni-Mo fourth-nearest atomic interaction energy on the precipitation mechanism of Ni75Al14Mo11 alloy was investigated with the phase field model based on the microscopic diffusion equation.The structure evolution on atomic scale,the composition and long-range order parameters of the precipitates were analyzed to explore the ordering and clustering,atoms reverse precipitation and coarsening occurred in precipitation process of Ni75Al14Mo11 alloy.The results show that the increase of the nearest/the third Ni-Mo atomic interaction energy can promote the atoms clustering and ordering,yet restrain the later Nickel atoms reverse precipitation and coarsening;the influence of the second/the fourth Ni-Mo atomic interaction energy is contrary to that of the nearest/the third;and the influence of the outermost atomic interaction energy on clustering and ordering is the largest in the same condition.