Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum Alloy

In this paper, the microstructure changes of an Al–6.8Zn–2Mg–2Cu–0.1Zr–0.2Sc alloy for shipbuilding under different T6 states were investigated. The effect of aging temperature on the electrochemical corrosion behavior of the alloy was analyzed by means of SEM, EDS, and TEM, and the corrosion mechan...

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Main Authors: Boqian Cai, Xiaolong Liu, Yang Yi, Hongyang Li, Fanian Shi
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Crystals
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Online Access:https://www.mdpi.com/2073-4352/15/2/107
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author Boqian Cai
Xiaolong Liu
Yang Yi
Hongyang Li
Fanian Shi
author_facet Boqian Cai
Xiaolong Liu
Yang Yi
Hongyang Li
Fanian Shi
author_sort Boqian Cai
collection DOAJ
description In this paper, the microstructure changes of an Al–6.8Zn–2Mg–2Cu–0.1Zr–0.2Sc alloy for shipbuilding under different T6 states were investigated. The effect of aging temperature on the electrochemical corrosion behavior of the alloy was analyzed by means of SEM, EDS, and TEM, and the corrosion mechanism was revealed. The results show that the bean-shaped Al<sub>3</sub>(Sc, Zr) phase is formed in the T6 alloy. The matrix-precipitated phase is mainly the GP zone at 120 °C. At 150 °C, part of the GP zone is transformed into the η′ phase, and at 180 °C, it is mainly η′ phase + η phase. After electrochemical testing in a 3.5 wt.% NaCl solution, it was found that the Cu content in the grain boundary η phase increased with the increase in aging temperature, the potential near the grain boundary increased, and the corrosion resistance increased. At the same time, the grain boundary precipitates were coarsened and distributed intermittently, which hindered the formation of corrosion channels and improved the corrosion resistance of the alloy. The corrosion mechanism of the alloy after aging at 120 °C/150 °C was mainly intergranular corrosion and pitting corrosion, while the corrosion mechanism after aging at 180 °C was mainly pitting corrosion.
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spelling doaj-art-03c75a66cc7d45dbaee9b9e3304f80f52025-08-20T03:12:18ZengMDPI AGCrystals2073-43522025-01-0115210710.3390/cryst15020107Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum AlloyBoqian Cai0Xiaolong Liu1Yang Yi2Hongyang Li3Fanian Shi4School of Environmental and Chemical Engineering, Shenyang University of Technology, Shenyang 110870, ChinaSchool of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, ChinaShenyang Xinghua Aviation Electrical Co., Ltd., AVIC, Shenyang 110144, ChinaSchool of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, ChinaSchool of Environmental and Chemical Engineering, Shenyang University of Technology, Shenyang 110870, ChinaIn this paper, the microstructure changes of an Al–6.8Zn–2Mg–2Cu–0.1Zr–0.2Sc alloy for shipbuilding under different T6 states were investigated. The effect of aging temperature on the electrochemical corrosion behavior of the alloy was analyzed by means of SEM, EDS, and TEM, and the corrosion mechanism was revealed. The results show that the bean-shaped Al<sub>3</sub>(Sc, Zr) phase is formed in the T6 alloy. The matrix-precipitated phase is mainly the GP zone at 120 °C. At 150 °C, part of the GP zone is transformed into the η′ phase, and at 180 °C, it is mainly η′ phase + η phase. After electrochemical testing in a 3.5 wt.% NaCl solution, it was found that the Cu content in the grain boundary η phase increased with the increase in aging temperature, the potential near the grain boundary increased, and the corrosion resistance increased. At the same time, the grain boundary precipitates were coarsened and distributed intermittently, which hindered the formation of corrosion channels and improved the corrosion resistance of the alloy. The corrosion mechanism of the alloy after aging at 120 °C/150 °C was mainly intergranular corrosion and pitting corrosion, while the corrosion mechanism after aging at 180 °C was mainly pitting corrosion.https://www.mdpi.com/2073-4352/15/2/107age-hardening aluminum alloyAl–6.8Zn–2Mg–2Cu–0.1Zr–0.2Scaging temperatureelectrochemical corrosion behavior
spellingShingle Boqian Cai
Xiaolong Liu
Yang Yi
Hongyang Li
Fanian Shi
Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum Alloy
Crystals
age-hardening aluminum alloy
Al–6.8Zn–2Mg–2Cu–0.1Zr–0.2Sc
aging temperature
electrochemical corrosion behavior
title Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum Alloy
title_full Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum Alloy
title_fullStr Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum Alloy
title_full_unstemmed Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum Alloy
title_short Influence of Aging Temperature on the Electrochemical Corrosion Behavior of an Age-Hardening 7xxx Aluminum Alloy
title_sort influence of aging temperature on the electrochemical corrosion behavior of an age hardening 7xxx aluminum alloy
topic age-hardening aluminum alloy
Al–6.8Zn–2Mg–2Cu–0.1Zr–0.2Sc
aging temperature
electrochemical corrosion behavior
url https://www.mdpi.com/2073-4352/15/2/107
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AT yangyi influenceofagingtemperatureontheelectrochemicalcorrosionbehaviorofanagehardening7xxxaluminumalloy
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