Corrosion behavior of a five-layer Al alloy composite plate in NaCl solution
Dejing Zhou, Mingyang Wang, Yuanyuan Ji, Zhe Liu, Zhiming Gao, Wenbin Hu, Yuhua Guo
Abstract
Purpose This paper aims to investigate the electrochemical corrosion behavior of a five-layer Al alloy composites (4343/4047/3003/4047/4343) with a thickness of 0.2 mm in NaCl solution. Design/methodology/approach Electrochemical impedance spectroscopy, polarization curve and morphology analyses were used to study the corrosion behavior of the Al alloy composites from cross-sectional and plane directions. Findings The corrosion resistance of the surface from the plane direction was higher than that from the cross sections. Si-enrich particles were observed in the outer 4047/4343 layer, and AlFeCuMnBi phases were identified in the core 3003 layer. The galvanic coupling between the Si-enrich particle and the Al matrix accelerated the dissolution Al matrix. Originality/value This work lays the experimental foundation for corrosion mechanism of the Al alloy composite plate.