Cycle-dependent creep-fatigue deformation and life predictions in a nickel-based superalloy at elevated temperature
Cycle-dependent creep-fatigue deformation and life predictions in a nickel-based superalloy at elevated temperature
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DOI：
10.1016/j.ijmecsci.2021.106628
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发表时间：
2021-07-13
影响因子：
7.3
通讯作者：
Tu, Shan-Tung
中科院分区：
文献类型：
--
作者：
Cheng, Lv-Yi;Wang, Run-Zi;Tu, Shan-Tung
在650 ℃下对镍基高温合金进行了一系列具有不同停留时间和应变比的应变控制蠕变疲劳试验。针对蠕变疲劳行为的力学理解，采用非统一的本构框架来描述宏观循环变形过程，以理解蠕变疲劳行为。然后，定量评估蠕变疲劳损伤的定量确定的逐循环应变能密度耗尽（SEDE）的方法。应变比和保压时间对蠕变-疲劳寿命偏差的影响可以很好地揭示由所提出的寿命模型，其中所有的数据点预测在+/- 1.5的误差带。特别是基于三区蠕变机理，进一步提高了长停留时间下的寿命预测能力。
A series of strain-controlled creep-fatigue tests with various dwell times and strain ratios are carried out on a nickel-based superalloy at 650 degrees C. Aiming at the mechanical understanding of creep-fatigue behavior, a non unified constitutive framework is used to describe macroscopic cyclic deformation process to understand creep fatigue behavior. Afterward, the quantitative evaluation of creep-fatigue damage is quantitatively determined by the cycle-by-cycle strain energy density exhaustion (SEDE) approach. The effects of strain ratio and dwell time on creep-fatigue life endurances can be well revealed by the proposed life model, where all the data points are predicted within +/- 1.5 error band. Particularly, life prediction capacities with long dwell times are further improved based on three-regime creep mechanism.