[011]取向镍基单晶合金高温蠕变期间γ′相定向粗化行为研究

Phase Morphology Evolution of a Single Crystal Nickel-Base Superalloy in the [011] Direction During the Tensile Creep

摘要:

研究了980 ℃, 200 MPa拉伸蠕变期间[011]取向镍基单晶高温合金中γ′相的演化方式。采用有限元方法计算了单晶合金在有/无外加载荷时Von Mises应力及弹性应变能密度在γ和γ′两相中的分布。结果表明：沿[011]取向施加拉伸应力时，与应力轴呈45°角基体通道(roof)的Von Mises应力远高于与应力轴平行的基体通道(gable)中的Von Mises应力，两通道中应变能密度的差异驱动γ′相形成元素从变形较大的通道向变形较小的通道扩散，而γ相形成元素反向扩散，导致γ′相沿[010]和[1

Abstract:

By means of finite elements analysis,an investigation has been made for the directional coarsening manners and evolutional rule of γ′ precipitates in a single crystal nickel-base superalloy with [011] orientation during tensile creep at 980 ℃ and 200 MPa. Results show that the von Mises stress in the matrix channel that is 45° with respect to the loading direction is larger than that in the matrix channel that is parallel to the loading direction when external loads applied along the [011] direction. The strain energy change in two kinds of matrix channel is the driving force for the γ′ directional coarsening, the γ′ phase developed along the [010] and [100] and perpendicular to the [001] orientations, and formed lamellar raft morphology inclined 45° angle to the tensile stress axis