Designing a gradient structure in a Ni-based superalloy to improve fretting fatigue resistance at elevated temperatures through an ultrasonic surface rolling process. (March 2023)

• Record Type: Journal Article
• Authors: Yang, Jing; Liu, Daoxin; Fan, Kaifa; Liu, Yanjie; Ren, Zhencheng; Liu, Dan; Xu, Xingchen; Jia, Tianyi; Zhang, Hao; Ye, Chang
• Is Part Of: International journal of fatigue. Volume 168(2023)
• Publication Date: 2023-03
• Subjects: Ultrasonic surface rolling process -- Fretting fatigue at elevated temperature -- GH4169 superalloy -- Gradient nanostructure -- Compressive residual stress; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2022.107397
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: The fretting fatigue of gradient nanostructured GH4169 was significantly improved at high temperature. Compressive residual stress plays a leading factor in improving fretting fatigue resistance at high temperature. Compressive residual stress of gradient nanostructured GH4169 was much more stable than that of non-gradient nanostructured alloy. The mechanism of fretting fatigue of gradient nanostructured GH4169 at high temperature was revealed. The mechanism of stability of compressive residual stress was revealed. Abstract: In this study, a gradient nanostructured GH4169 superalloy was prepared by ultrasonic surface rolling process (USRP), and the fretting fatigue resistance was investigated at elevated temperatures. After USRP, a high density of deformation twins, stacking faults and dislocations as well as precipitates were observed in the surface of the gradient nanostructured GH4169 superalloy when examined using transmission electron microscopy. Factor separation analysis was carried out to determine the leading factor for the improvement of the fretting fatigue properties of GH4169 at elevated temperatures, and the compressive residual stress was found to be the leading factor. The mechanism was determined to be dislocation movement that can be pinned by deformation twins, stacking faults and precipitates and, thus, is able to stabilize the compressive residual stress at elevated temperatures. As a result, the USRP-treated GH4169 with gradient nanostructure was found to have the highest fretting fatigue resistance at elevated temperatures.