High-temperature low-cycle fatigue experiments were performed at different strain rates on nickel-based superalloy MAR-M247. Furthermore, slow-fast, fast-slow and dwell-fatigue tests were conducted. The deformation, damage and lifetime behaviour as a function of strain rate and cycle shape were observed. Results show that the lifetime decreases with decreasing strain rate, indicating the negative influence of time-dependent creep and oxidation mechanisms. The lifetimes of slow-fast and dwell-fatigue tests are lower than those for fast-slow tests, although the mean stress is compressive in slow-fast and dwell-fatigue tests and tensile in fast-slow tests. Slow-fast and dwell-fatigue tests lead to grain boundary cavitation.

在镍基高温合金 MAR-M247 上进行了不同应变率的高温低周疲劳试验。此外，还进行了慢-快、快-慢和驻留疲劳试验。观察了作为应变率和循环形状函数的变形、损坏和寿命行为。结果表明，寿命随着应变速率的降低而降低，表明时间依赖性蠕变和氧化机制的负面影响。慢-快和驻留疲劳测试的寿命比快-慢测试的寿命短，尽管平均应力在慢-快和驻留疲劳测试中是压缩的，而在快-慢测试中是拉伸的。慢速和驻留疲劳试验会导致晶界空化。