In order to reveal the shot peening (SP) strengthening mechanism on the high-temperature fretting fatigue performance of nickel-based single crystal (NBSC) tenon attachment, fretting fatigue tests under three load conditions were carried out at 600 ℃. The results showed that the fretting fatigue life of SP NBSC tenon attachment could be increased to 357.53 % of that of non-SP NBSC tenon attachment. SP changed the fretting fatigue crack initiation site from the contact surface to the subsurface. The larger the peak load was, the closer the crack initiation site was to the contact surface. SP changed the fretting fatigue crack propagation path, and the crack propagation deviated from the original direction approximately perpendicular to the contact surface. SP increased the microhardness by 28.1 %, induced −1098 MPa maximum compressive residual stress (CRS) and generated a mean geometrically necessary dislocation (GND) density of 7.55× 10 m near the surface. The micro convex bodies and greater microhardness alleviated the wear damage, and the increased dislocation density and CRS enhanced the inhibition of crack initiation and propagation, which were the strengthening mechanism of SP to improve the fretting fatigue performance of NBSC tenon. This work aimed to provide support for the long-life manufacturing of NBSC turbine blades.

中文翻译：

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喷丸强化对改善镍基单晶高温合金榫头高温微动疲劳性能的影响


为了揭示喷丸强化机制对镍基单晶榫头附件高温微动疲劳性能的影响，在600 ℃下进行了三种载荷条件下的微动疲劳试验。结果表明，SP NBSC榫头的微动疲劳寿命比非SP NBSC榫头的微动疲劳寿命提高了357.53%。 SP将微动疲劳裂纹萌生位置从接触表面改为亚表面。峰值载荷越大，裂纹萌生位置越靠近接触面。 SP改变了微动疲劳裂纹扩展路径，裂纹扩展偏离原来方向近似垂直于接触面。 SP 使显微硬度提高了 28.1%，诱导了 -1098 MPa 最大残余压缩应力 (CRS)，并在表面附近产生了 7.55× 10 m 的平均几何必要位错 (GND) 密度。微凸体和较大的显微硬度减轻了磨损损伤，位错密度的增加和CRS增强了对裂纹萌生和扩展的抑制，这是SP改善NBSC榫头微动疲劳性能的强化机制。这项工作旨在为NBSC涡轮叶片的长寿命制造提供支持。