Low-cycle fatigue behavior and corrosion mechanism of pre-corroded 2A70-T6 aluminum alloy
Anti-Corrosion Methods and Materials
ISSN: 0003-5599
Article publication date: 31 January 2020
Issue publication date: 11 March 2020
Abstract
Purpose
In summary, it can be found that the current research on the simulation of natural atmospheric dry–wet alternating accelerated corrosion mainly focused on the study of electrochemical corrosion process and the study of corrosion rate; the micro-pre-corrosion mechanism of materials in this environment, especially for materials. The specific effects of fatigue and fracture performance still lack detailed research. Accordingly, this study aims to more realistically simulate the effect of natural atmospheric corrosion environment on the corrosion resistance and fatigue performance of aircraft skin.
Design/methodology/approach
In this study, the uniaxial strain control method was used to test the fatigue performance of pre-corrosion samples under simulated natural atmospheric corrosion using MTS809 tensile-torque composite fatigue machine. Scanning electron microscopy, X-ray energy spectrum analysis, atomic force microscopy and X-ray diffraction analysis were used. Fatigue fracture, corrosion morphology and corrosion products were analyzed.
Findings
The results show that the deep corrosion pit caused by pre-corrosion environment leads to multi-source initiation of crack; the fatigue life of pre-corroded sample decreases by about one-half, chloride ion invades the material and promotes intergranular corrosion; life prediction results show that the natural atmospheric corrosive environment mainly affects the plastic term in the Manson–Coffin formula resulting in a decrease in fatigue life.
Originality/value
Innovative experimental schemes and materials are used and the test temperature and relative humidity are strictly controlled. The corrosion failure mechanism of 2A70-T6 aluminum alloy under alternating wet and dry accelerated corrosion environment and its influence on fatigue behavior were obtained.
Keywords
Acknowledgements
Financial support was provided by the National Natural Science Foundation of China (No.51301115,No.51701133), the Opening Project of Sichuan Province University Key Laboratory of Bridge Non-destruction Detecting and Engineering Computing (2018QYJ03,2018QZY01), the Project of Key Laboratory of Corrosion and Protection of Sichuan Province Materials (2012CL10,2016CL17), the Project of Sichuan Province Department of Education (16ZB0255,18ZA0352), the Project of Key Lab in Sichuan Colleges on Industry Process Equipment and Control Engineering (GK201501,GK201808,GK201816) and the Talent Introduction Project of Sichuan University of Science and Engineering (2015RC34).
Citation
Li, H., Fu, L., Lin, L., Chen, Y., Luo, Y., Li, X., Xie, W. and Wang, Q. (2020), "Low-cycle fatigue behavior and corrosion mechanism of pre-corroded 2A70-T6 aluminum alloy", Anti-Corrosion Methods and Materials, Vol. 67 No. 2, pp. 228-239. https://doi.org/10.1108/ACMM-07-2019-2161
Publisher
:Emerald Publishing Limited
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