镍基定向结晶合金蠕变损伤的细观模型

Meso Approaches for the Creep Damage Behavior of Nickel_Base Directionally Solidified Superalloys

针对镍基定向结晶合金的蠕变变形和损伤，本文建立了有限元和自洽两种晶体滑移细观模型·在这两种模型中同时考虑了晶粒滑移损伤和晶界损伤·通过一组镍基单晶合金和一组特殊结晶取向的定向结晶合金标定了模型参数·数值分析结果表明，这两种模型都可以比较准确地描述定向结晶合金的蠕变损伤变形和失效规律，尤其是定向结晶合金蠕变性能的结晶取向相关性·

A self_consistent creep damage constitutive model and a finite element model have been developed for nickel_base directionally solidified superalloys. Grain degradation and grain boundary voiding are considered. The model parameters are determined from the creep test data of a single crystal and a directionally solidified superalloy with a special crystallographic orientation. The numerical analysis shows that the modeled creep damage behaviors of nickel_base directionally solidified superalloys with different crystallographic orientations are in good agreement with the experimental data.