Effect of aging treatment on microstructure and corrosion behavior of Al-Zn-Mg aluminum alloy in aqueous solutions with different aggressive ions
- Resource Type
- Authors
- Pan Liu; Fahe Cao; Jianqing Zhang; Zuosi Yu; Cuiping Yang; Lulu Hu; Qinhao Zhang; Jiming Hu
- Source
- Journal of Materials Science & Technology. 64:85-98
- Subject
- Materials science
Polymers and Plastics
Alloy
chemistry.chemical_element
02 engineering and technology
engineering.material
010402 general chemistry
01 natural sciences
Corrosion
Aluminium
Materials Chemistry
Polarization (electrochemistry)
Aqueous solution
Mechanical Engineering
Metals and Alloys
021001 nanoscience & nanotechnology
Microstructure
Grain size
0104 chemical sciences
Dielectric spectroscopy
chemistry
Chemical engineering
Mechanics of Materials
Ceramics and Composites
engineering
0210 nano-technology
- Language
- ISSN
- 1005-0302
The microstructure and corrosion behavior of Al-Zn-Mg alloy (namely 7×××) after natural aging treatment (NAT) and artificial aging treatment (AAT) in aqueous NaCl solutions containing different aggressive ions have been investigated in current work. Results of microstructure characterization demonstrate that the aging treatment has a great influence on the grain size and precipitates. The grain size is relatively sizeable and no evident precipitates are observed in alloy after NAT comparable with that after AAT. The electrochemical corrosion behavior of alloy was studied by polarization curve and electrochemical impedance spectroscopy (EIS). The corrosion potential (Ecorr) of the aluminum alloy is more negative in 3.5 wt.% NaCl containing 0.052 wt.% NaHSO3 solution than that in 3.5 wt.% NaCl solutions with or without 0.907 wt.% NaHCO3. Charge transfer resistance (Rct) results reveal that alloy after AAT has an enhancement of corrosion resistance compare with that after NAT. With the immersion time increasing, mostly pitting spreads over the surface of the alloy only in NaCl solution, whereas exfoliation corrosion mainly occurs in NaCl solutions containing NaHSO3 or NaHCO3.