Abstract Based on the metallographic observation, the microstructure evolution of nickel-based single crystal superalloy under thermomechanical fatigue (TMF) loading is investigated, and respective phenomenological models of damage and rafting are developed. Considering that the deformation behaviour of material is closely related to their microstructures, new variables involving rafting evolution are incorporated to modify the hardening rule in order to overcome the inaccurate prediction in stable stage of ratcheting behaviour. Furthermore, by combining the continuum damage mechanics, a modified crystal plasticity constitutive model is proposed, and the ratcheting behaviour during the whole TMF lifetime, as well as hysteresis loops, can be simulated accurately.

中文翻译：

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考虑微观结构演化的镍基单晶高温合金在热机械疲劳载荷下棘轮行为的本构模型

摘要 基于金相观察，研究了镍基单晶高温合金在热机械疲劳（TMF）加载下的显微组织演变，建立了各自的损伤和漂流现象模型。考虑到材料的变形行为与其微观结构密切相关，引入漂流演化的新变量来修改硬化规则，以克服棘轮行为稳定阶段预测不准确的问题。此外，通过结合连续介质损伤力学，提出了一种改进的晶体塑性本构模型，可以准确地模拟整个 TMF 寿命期间的棘轮行为以及滞后回线。