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Effect of alternate corrosion factors on multiaxial low-cycle fatigue life of 2024-T4 aluminum alloy

Authors :
Yajun Chen
Jian Zhou
Chenchen Liu
Fusheng Wang
Source :
Journal of Alloys and Compounds. 772:1-14
Publication Year :
2019
Publisher :
Elsevier BV, 2019.

Abstract

Due to the seawater splash, rain water scouring and prolonged exposure, the aircrafts serviced in sea-coast or marine environment always suffered liquid corrosion effects under certain temperature. 2024-T4 aluminum alloy had been widely used in aircrafts fuselage. During service, the actual process was close to the alternate mode of “Ground Corrosion + Air Fatigue”, in which alternate corrosion factors had greatly effects on multiaxial fatigue life of 2024-T4 aluminum alloy. For the purpose of evaluating the influence of alternate corrosion time, corrosion temperature, corrosion solution flow rate and pH value on the fatigue performance, a multi-parameter regulated liquid corrosion device was designed. Multiaxial fatigue tests were performed under constant amplitude sinusoidal wave loading with constant tension-torsion ratio 3 in air. The fracture was observed by scanning electron microscope. The results indicated a reduction tendency of multiaxial fatigue life with the increase of alternate corrosion time, corrosion temperature and corrosion solution flow rate as well as the decrease of pH value. The influence order of relevant factors was: alternate corrosion time > corrosion temperature > corrosion solution flow rate > solution pH value. The effects of alternate time and temperature immersed in solution on corrosion resistance of 2024-T4 aluminum alloy are investigated by potentiodynamic polarization experiments and electrochemical impedance spectroscopy (EIS) tests. The observed mechanical behavior and associated phenomena were directly linked to microstructure characteristics such as corrosion pits and micro-cracks. The cyclic hardening appeared in both axial and tangential direction at the beginning stage. With the consideration of corrosion effect on the fatigue property, the equivalent corrosion life was proposed to characterize the influence of corrosion and to predict the alternate corrosion - fatigue life. Fine results were obtained with all data in 2× scatter band.

Details

ISSN :
09258388
Volume :
772
Database :
OpenAIRE
Journal :
Journal of Alloys and Compounds
Accession number :
edsair.doi...........8ae106b26224e1396bf67ba1e63cdf25
Full Text :
https://doi.org/10.1016/j.jallcom.2018.08.282