Effects of secondary orientation on crack closure behavior of nickel-based single crystal superalloys. (February 2016)

• Record Type: Journal Article
• Authors: Qiu, Wenhui; He, Zhiwu; Fan, Ya-Nan; Shi, Hui-Ji; Gu, Jialin
• Is Part Of: International journal of fatigue. Volume 83:Part 2(2016)
• Page Start: 335
• Page End: 343
• Publication Date: 2016-02
• Subjects: Secondary orientation -- Crack closure -- Nickel-based single crystal superalloy -- In-situ SEM fatigue tests; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2015.11.004
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: Crack closure behavior of a nickel-based single crystal superalloy was studied. Specimens in two orientations exhibit different cracking manners. Secondary orientation effects on crack closure behavior were found. Abstract: The crack closure behavior of a nickel-based single crystal (SC) superalloy was studied based on in-situ SEM fatigue tests. Specimens in two different secondary orientations were tested at 600 °C. A model considering the anisotropy of SC superalloys was developed to analyze crack closure behavior. The results show that specimens in two orientations exhibit different cracking modes. For specimen [0 0 1]/[0 1 0], roughness-induced crack closure effect is dominant in crack closure behavior and crack closure effect is constant during crack propagation process. However, for specimen [0 0 1]/[1 1 0], plasticity-induced crack closure effect is dominant in crack closure which becomes enhanced as crack grows.