镍基单晶合金蠕变研究:试验、机理及材料模型

Creep research of Ni-based single crystal superalloy: experiment,mechanism and material model

在镍基单晶合金高温蠕变建模研究工作的第一部分,通过对DD6镍基单晶合金不同中断时间的高温蠕变试验及透射电镜(TEM)观察,结合单晶合金蠕变机理的研究成果阐明了单晶高温蠕变的机理,并从Orowan方程出发,在晶体塑性理论框架下建立描述晶体滑移系上位错演化规律的方程,发展了以位错密度变化表征镍基单晶高温蠕变的材料模型.该模型考虑了较宽温度与载荷范围内单晶的主要蠕变机理,可较好地建模750~1100℃范围内镍基单晶的各向异性蠕变行为.

A new creep model of Ni-based single crystal superalloy was presented.Differential constitutive equations were based on transmission electron microscope(TEM) observation from creep experiment of single superalloy DD6 and mechanisms of single crystal superalloys generation 1 and 2.The non-linear equation was developed under the framework of crystal plasticity and derived from Orowan equation and evolution of dislocation density developed during the creep deformation process with effect of resolving stress le...