| 粉末冶金镍基高温合金FGH96高温疲劳寿命分散性特征 |
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| 引用本文： | 苗国磊,杨晓光,石多奇.粉末冶金镍基高温合金FGH96高温疲劳寿命分散性特征[J].航空动力学报,2017,32(2):424-428. |
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| 作者姓名： | 苗国磊 杨晓光 石多奇 |
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| 作者单位： | 1.北京航空航天大学 能源与动力工程学院，北京 100191 |
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| 基金项目： | 国家重点基础研究发展计划（2015CB057401） |
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| 摘 要： | 通过宽载荷水平大子样试验研究了缺陷对粉末冶金镍基高温合金FGH96的疲劳寿命分散性的影响，获得FGH96在宽载荷水平下的疲劳寿命分布特征.通过扫描电镜对疲劳失效断口进行统计分析，揭示缺陷在不同载荷条件下的作用.结果表明:①FGH96中导致疲劳失效的缺陷主要为非金属夹杂；②在高应力水平下（1200，1100MPa）下，导致表面萌生裂纹的夹杂是最差疲劳寿命的主导因素，使得疲劳寿命分散性较大；③在中间应力水平（1000MPa）下，在材料内部萌生裂纹的夹杂并不影响疲劳寿命的分散性；④在低应力水平（900MPa）下，疲劳破坏均萌生于内部，在材料内部夹杂处萌生的裂纹并不影响疲劳寿命的分散性.因此，在高应力水平下的寿命预测需要考虑缺陷信息.
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| 关 键 词： | 粉末冶金高温合金 缺陷 疲劳寿命分散性 载荷水平 大子样 |
| 收稿时间： | 2016/3/31 0:00:00 |
Behavior of fatigue life variability of nickel based powder metallurgy superalloy FGH96 at elevated temperature |
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| MIAO Guo-lei,YANG Xiao-guang,SHI Duo-qi.Behavior of fatigue life variability of nickel based powder metallurgy superalloy FGH96 at elevated temperature[J].Journal of Aerospace Power,2017,32(2):424-428. |
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| Authors: | MIAO Guo-lei YANG Xiao-guang SHI Duo-qi |
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| Abstract: | The effects of defects on fatigue life variability of nickel based powder metallurgy superalloy FGH96 were investigated by conducting fatigue tests in large sample case at different stress levels. The fatigue life distribution characteristics of FGH96 were obtained. The fatigue fracture analysis of all the tests by scanning electron microscopy showed: (1) the defects contributing to fatigue failure mainly were non metallic inclusions; (2) under higher stress levels (1200, 1100MPa), inclusion in the surface was the life limiting factor, resulting larger life variability; (3) in the middle stress levels (1000MPa), crack initiation in the internal inclusion did not affect the fatigue life variability; (4) under lower stress level (900MPa), fatigue crack was initiated in the internally, there were no effects of internal inclusions on fatigue life variability. Therefore, the defects need to be considered in the life prediction at higher stress level. |
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| Keywords: | powder metallurgy superalloy at elevated temperature defects fatigue life variability stress level large sample |
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