应变能对Ni75Al15V10合金预析出相影响的微观相场研究

Study for the Effect of Strain Energy on Pre-Precipitation Phase in Ni75Al15V10 Alloy Using the Microscopic Phase-Field Method

摘要:

采用微观相场方法，以Ni75Al15V10合金为例研究了应变能对预析出相的影响。研究发现：合金沉淀早期的应变能影响预析出相L10的析出。无应变能作用时，体系中没有预析出相L10相出现；应变能越大，L10预析出相的孕育期越短，析出量增加，稳定存在时间越长，且体系所析出的L10相的结构特征越明显。应变能较小时，无序基体有些区域先析出L10相，随后所析出的L10相转变为L12相，而在有些区域却直接析出L12相；当应变能较大时，基体大范围先析出L10相，随后部分L10预析出相溶解，只有未溶解部分最终能转变为L12相。

Abstract:

The effect of strain energy on pre-precipitation phase in Ni75Al15V10 alloy was studied using the microscopic phase-field method. It is found that the initial state of strain energy in the alloy has an effect on precipitation of L10 phase. L10 phase does not precipitate unless the effect of strain energy is considered. The larger the strain energy is, the shorter the nucleation incubation periods of L10 phase are, and the more obvious the characteristics of precipitated L10 phase are. Meantime the volume fraction and the lifetime of precipitated L10 phase also increase as the strain energy increases. When the strain energy is small, L10 phase precipitates in some areas of the disordered matrix firstly, and then the transformation from L10 to L12 phase occurs; however, in other regions L12 phase precipitate directly. When the strain energy becomes larger, L10 phase precipitate in most areas of the matrix, followed by part of these L10 phase dissolving, and the undissolved L10 phase would transform into L12 phase finally.