Material Engineering and Mechanical Manufacturing

Effect of long-term atmospheric corrosion on fatigue behavior of 2A12-T4 aluminum structures

  • ZHANG Teng ,
  • HE Yuting ,
  • GAO Chao ,
  • HOU Bo ,
  • LI Changfan
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  • Aeronautics and Astronautics Engineering College, Air Force Engineering University, Xi'an 710038, China

Received date: 2015-01-07

  Revised date: 2015-02-06

  Online published: 2015-02-10

Supported by

National Natural Science Foundation of China (51475470, 51201182)

Abstract

Fatigue tests on 2A12-T4 aluminum alloy plate specimens, bolt interference fitted specimens and bolt interference fitted specimens with cold expansion are carried out after the specimens are exposed in Wanning, Hainan Province for 7 years, 12 years and 20 years. Corrosion morphologies, fatigue morphologies of fracture surfaces and side surfaces beside fracture site are analyzed. Furthermore, origins and mechanisms of fatigue characters, such as the positions of cracks initiate, the fracture sites of specimens, the change laws of fatigue lives, etc., are discussed. The results show that the fatigue lives of plate specimens and interference fitted specimens with cold expansion after being exposed for 20 years are almost the same as those of the specimens exposed for 12 years, while the fatigue lives of interference fitted specimens continue to decrease. The decrease of local intensity ranks in the order: section of interference fitted hole > section of untreated material > section of interference fitted hole with cold expansion. The corrosion susceptibility on the mid-area of L-S surface is weaker than that of L-T surface and on the side-area of L-S surface. The sites where intergranular corrosion occurs on the L-S surface become potential sources of fatigue cracking, and dense damage on the L-S surface due to long-term atmospheric corrosion is the main cause that the fatigue lives of plate specimens and interference fitted specimens with cold expansion do not decrease after 20 years of exposure than 12 years.

Cite this article

ZHANG Teng , HE Yuting , GAO Chao , HOU Bo , LI Changfan . Effect of long-term atmospheric corrosion on fatigue behavior of 2A12-T4 aluminum structures[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2015 , 36(7) : 2444 -2456 . DOI: 10.7527/S1000-6893.2015.0044

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