Abstract: The fretting fatigue behaviors of a nickel-based single crystal superalloy in contact with a powder metallurgy alloy at 600 °C are investigated. Fretting fatigue tests are conducted by using a novel high temperature fretting fatigue test apparatus that is developed, and the crystal plasticity finite element method is used to analyze the contact stress and activations of slip systems. The results show that the fretting conditions are partial slip regime for all loading conditions, and severe wear damage occurs across the slip region, which is accompanied by surface delamination and micro crack. Fretting fatigue cracks mainly initiate at the contact leading edge area, i.e., the stress concentration zone. The cracks grow along the (100) plane when multiple octahedral slip systems are activated simultaneously, or could be eliminated by wear. Considering the effects of both crystallographic slip and wear on the fretting fatigue damage, an improved fretting fatigue damage parameter, RA, is proposed to predict the fretting fatigue life. The predicted results agree well with the test results.

中文翻译：

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镍基单晶高温合金高温微动疲劳行为的实验与数值研究

摘要：研究了镍基单晶高温合金与粉末冶金合金在 600 °C 接触时的微动疲劳行为。采用研制的新型高温微动疲劳试验装置进行微动疲劳试验，采用晶体塑性有限元法分析滑移系统的接触应力和活化。结果表明，微动条件是所有加载条件下的部分滑动状态，滑动区域发生严重磨损损伤，并伴有表面分层和微裂纹。微动疲劳裂纹主要发生在接触前缘区域，即应力集中区。当多个八面体滑移系统同时被激活时，裂纹沿 (100) 平面扩展，或者可以通过磨损消除。考虑到晶体滑移和磨损对微动疲劳损伤的影响，提出了一种改进的微动疲劳损伤参数 RA 来预测微动疲劳寿命。预测结果与测试结果吻合良好。