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Retrogression on corrosion behavior of spray formed Al-7075

Published online by Cambridge University Press:  27 June 2017

Ruiming Su ,
Jianhao Su ,
Yingdong Qu ,
Junhua You  and
Rongde Li
Ruiming Su*
Affiliation:
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
Jianhao Su*
Affiliation:
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
Yingdong Qu
Affiliation:
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
Junhua You
Affiliation:
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
Rongde Li
Affiliation:
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
*
a) Address all correspondence to this author. e-mail: suruiming1984@gmail.com
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Abstract

The effects of retrogression and re-aging (RRA) treatment on intergranular corrosion (IGC), exfoliation corrosion (EXCO), stress corrosion cracking (SCC) behavior and microstructure of spray formed Al-7075 were investigated by a scanning electron microscope, a transmission electron microscope, slow strain rate test, and EXCO and IGC test. The results show that the precipitates are redissolved in the matrix of the alloy after retrogression at 200 °C for a suitable time (8 min), and the grain boundary precipitates are discrete and the obvious precipitate free zones are left at the grain boundaries. After RRA with suitable retrogressed time, thin homogeneous dispersive precipitates are separated out again in the matrix. After retrogression at 200 °C for 8 min and re-aging, the ultimate tensile strength, elongation, IGC depth, EXCO rating, and SCC index of spray formed Al-7075 are 791 MPa, 8.5%, 29.8 μm, EA, and 0.155, respectively.

Keywords

Al–alloyspray depositionstress corrosion crackingretrogressionslow strain rate test
Type
Articles
Information
Journal of Materials Research , Volume 32 , Issue 13 , 14 July 2017 , pp. 2621 - 2627
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Copyright
Copyright © Materials Research Society 2017 

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Footnotes

Contributing Editor: Jürgen Eckert

References

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