The brazing effect on the corrosion mechanism of a multilayer material with Cu
Abstract
Purpose
The purpose of this paper is to compare corrosion behavior of a modified multilayer material with Cu before and after brazing process.
Design/methodology/approach
Sea water acidified accelerated tests (SWAATs), potentiodynamic polarization tests and scanning electron microscopy were used to study the corrosion behavior and macro/micro structures. Results indicate that the corrosion mechanisms of the sheets before and after brazing process are completely different.
Findings
The un-brazed material is uniform corrosion, while the brazed material has a high sensitivity to localized corrosion and loses cathodic protection to the core. It is found that brazing process causes copper transition from the core alloy into eutectic phases in the cladding, leading to higher Ecorr and different potential distribution compared with those of un-brazed materials.
Originality/value
For the modified multilayer material after brazing, there are two stages of corrosion. First, corrosion attack takes place along eutectic phases in the cladding material, and then core alloy dissolves by forming a galvanic couple with the nobler residual cladding.
Keywords
Acknowledgements
Open Research Fund (RRME-KF1608) by Jiangsu Key Laboratory of Recycling and Reuse Technology for Mechanical and Electronic Products of China; Project (Grant Nos. 11405014) supported by National Natural Science Foundation of China; Project (BY2015043-02) supported by Jiangsu Science and Technology Department of China.
Citation
Yuan, T., Zhang, M.-d., Ni, J.-h., Chen, Y.-x. and Geng, F. (2017), "The brazing effect on the corrosion mechanism of a multilayer material with Cu", Anti-Corrosion Methods and Materials, Vol. 64 No. 6, pp. 664-671. https://doi.org/10.1108/ACMM-07-2016-1688
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited