Abstract
This work studies the influence of the microstructure on the corrosion mechanism and susceptibility of as-brazed aluminum sheet. Various microstructures are obtained using postbrazing heat treatments developed to enhance the corrosion resistance of an AA4xxx/AA3xxx brazing sheet. The heat treatment results in a decrease of the matrix Si content within the heat affected zone and an increase of the Si fraction in the α-Al(Fe-Mn)Si phase. Additionally, the effect of the heat treatment on the local electrochemical activity and corrosion properties are studied. The results indicate that the corrosion susceptibility of the as-brazed structure is diminished resulting from of an amendment of the local electrochemical behavior of the outer clad surface after the post-brazing heat treatment. Moreover, the potential difference between the clad material and core is increased, resulting in an improved sacrificial cathodic protection of the core by the re-solidified clad layer.
Original language | English |
---|---|
Pages (from-to) | 379-393 |
Journal | Corrosion: journal of science and engineering |
Volume | 73 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2017 |
Bibliographical note
Accepted Author ManuscriptKeywords
- Aluminum alloy
- Heat treatment
- Kelvin probe
- Microstructure
- Transmission electron microscopy