Improved corrosion resistance of aluminum brazing sheet by a post-brazing heat treatment

Improved corrosion resistance of aluminum brazing sheet by a post-brazing heat treatment

Norouzi Afshar, F. (Material Innovation Institute (M2i); Kavli institute of nanoscience Delft)
Tichelaar, F.D. (TU Delft QN/Zandbergen Lab; Kavli institute of nanoscience Delft)
Glenn, A. M. (CSIRO, Mineral Resources)
Taheri, P. (TU Delft (OLD) MSE-6)
Sababi, M. (TU Delft (OLD) MSE-6)
Terryn, H.A. (TU Delft (OLD) MSE-1; Vrije Universiteit Brussel)
Mol, J.M.C. (TU Delft (OLD) MSE-6)

2017

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.

Aluminum alloy
Heat treatment
Kelvin probe
Microstructure
Transmission electron microscopy

http://resolver.tudelft.nl/uuid:82be4414-055e-4a24-bd02-fd996f06e4c5

https://doi.org/10.5006/2210

2017-03-31

0010-9312

Corrosion: journal of science and engineering, 73 (4), 379-393

Accepted Author Manuscript

Institutional Repository

journal article

© 2017 F. Norouzi Afshar, F.D. Tichelaar, A. M. Glenn, P. Taheri, M. Sababi, H.A. Terryn, J.M.C. Mol