Influence of heat treatment on corrosion behaviour of Al?Zn?Mg?Cu?Zr?Sc alloy |
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| Authors: | Y P Xiao Q L Pan W B Li X Y Liu Y B He |
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| Affiliation: | 1. School of Materials Science and Engineering, Central South University, Changsha 410083, (P. R. China);2. Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education, Changsha 410083, (P. R. China);3. School of Civil Engineering, Hunan City University, Yiyang 413000, (P. R. China) |
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| Abstract: | Corrosion behaviour of different tempers (namely NA, UA, PA and OA) of Al? Zn? Mg? Cu? Zr? Sc alloy was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), optical microscopy (OM) and transmission electron microscopy (TEM). Over aged (OA) can decrease the susceptibility to exfoliation due to the discontinuous distribution of the η precipitates at the grain boundaries, cause a negative shift of the corrosion potential (Ecorr), and lead to the prolonging of the time of the appearance of two time constants in impedance diagrams. In addition, Al? Zn? Mg? Cu? Zr? Sc alloy with over aged treatment has an enhanced resistance to exfoliation corrosion. |
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| Keywords: | Al?Zn?Mg?Cu?Sc?Zr alloy Exfoliation corrosion Heat treatment Electrochemical impedance spectroscopy Polarization |
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