In-situ SEM study of fatigue micro-crack initiation and propagation behavior in pre-corroded AA7075-T7651
Song, Haipeng Liu, Changchun Zhang, Hao Du, Juan Yang, Xudong Leen, Sean B.
Song, Haipeng
Liu, Changchun
Zhang, Hao
Du, Juan
Yang, Xudong
Leen, Sean B.
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Publication Date
2020-04-18
Type
Article
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Citation
Song, Haipeng, Liu, Changchun, Zhang, Hao, Du, Juan, Yang, Xudong, & Leen, Sean B. (2020). In-situ SEM study of fatigue micro-crack initiation and propagation behavior in pre-corroded AA7075-T7651. International Journal of Fatigue, 137, 105655. doi: https://doi.org/10.1016/j.ijfatigue.2020.105655
Abstract
Fatigue micro-cracking behavior in pre-corroded AA7075-T7651 is analyzed by in-situ scanning electron microscopy (SEM) observation and SEM-based fractography. The experimental results show that (i) fatigue microcracks nucleated mainly from inclusions at the specimen notch and from corrosion pits on the specimen surface, (ii) pre-corrosion severity degree and maximum stress level significantly affected the extent and time of microcrack initiation. Corrosion pits are shown to play a crucial role in fatigue micro-crack propagation, due to crack deflection (light corrosion) and crack coalescence (severe corrosion). The growth rate of minor cracks was suppressed by pre-dominant rapid propagation of the main crack.
Publisher
Elsevier
Publisher DOI
10.1016/j.ijfatigue.2020.105655
Rights
Attribution-NonCommercial-NoDerivs 3.0 Ireland