Multiscale investigation of corrosion damage initiation and propagation in AA7075-T651 alloy using correlative microscopy

[Display omitted] •Corrosion damage evolution in AA 7075-T651 under potentiodynamic polarization was studied by correlative microscopy.•Concentric Corrosion Patterns were observed before the second breakdown potential due to induced magnetic field and a Lorentz force.•Exfoliation Corrosion led to a...

Full description

Saved in:
Bibliographic Details
Published in:Corrosion science 2021-06, Vol.185, p.109429, Article 109429
Main Authors: Niverty, Sridhar, Kale, Chaitanya, Solanki, Kiran N., Chawla, Nikhilesh
Format: Article
Language:English
Subjects:
Aluminum base alloys
Computed tomography
Concentric corrosion patterns
Correlative microscopy
Corrosion
Corrosion tests
Crack initiation
Damage
Electron backscatter diffraction
Evolution
Exfoliation corrosion
Fracture mechanics
Intergranular corrosion
Ion beams
Iron
Localized corrosion
Microscopy
Microstructure
Pitting (corrosion)
Potentiodynamic polarization
Propagation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •Corrosion damage evolution in AA 7075-T651 under potentiodynamic polarization was studied by correlative microscopy.•Concentric Corrosion Patterns were observed before the second breakdown potential due to induced magnetic field and a Lorentz force.•Exfoliation Corrosion led to a combination of intergranular and transgranular corrosion leading to extensive grain dissolution.•Al7Cu2Fe particle dissolution was observed due to selective dissolution of Fe, Al, leaving behind Cu-rich clusters within the particle. The evolution of the overall microstructure and contribution of constituent second phase particles during the accelerated corrosion of AA 7075-T651 warrants further scrutiny. A correlative microscopy-based approach was employed to study corrosion damage evolution in the microstructure of AA 7075-T651 subjected to potentiodynamic polarization. X-ray Computed Tomography (XCT) and scanning electron microscopy were used to track corrosion damage initiation and propagation globally and at specific regions of the microstructure starting from the first breakdown potential. Additionally, Focused Ion Beam and Electron Backscattered Diffraction were used to investigate local corrosion processes such as pitting and intergranular corrosion. Interesting concentric corrosion patterns, Fe-rich intermetallic particle dissolution and exfoliation corrosion were observed and mechanisms for the same have been proposed.
ISSN:0010-938X
1879-0496
DOI:10.1016/j.corsci.2021.109429