复杂应力状态下镍基单晶合金蠕变损伤规律研究

The Study of Multiaxial Creep Damage Behavior of Nickel-Base Single Crystal Superalloys

通过分析镍基单晶合金强化相了γ′在蠕变过程中的筏化规律，提出了复杂应力状态下同时考虑材质劣化和空洞损伤的各向异性晶体滑移损伤模型和寿命预测模型，所建模型得到了拉－扭薄壁圆筒蠕变试验的考核。

The crystallographic two-state-variable creep-damage constitutive and life predictive model presented in References [3, 4] has been used to study the creep behavior of nickel-base single crystal superalloys under multiaxial stress states. The material-type damage is dependent on the rafting of the precipitate γ′. The rafting can be simulated by the method of Monte Carlo and confirmed by the experimental results. The relationship between the material-type damage and the decrease in the free energy of rafted system has been assumed. Confirmed by the tension-torsion creep experiments of thin walled tubular of single crystal specimens, model can precisly predicted the creep behavior and rupture life of nickel-base single crystal superalloys under the multiaxial stress states