Electrochemical Properties of AlCu Alloys in 1M NaCl Solution

ALEJANDRA SILVINA ROMÁN; CLAUDIA MARCELA MÉNDEZ; CARLOS ENRIQUE SCHVEZOV; ALICIA ARES

Orlando

Simposio; Characterization of Minerals, Metals, and Materials; 2015

TMS

In this paper the structure of aluminum based alloys and their corrosion behavior by using different electrochemical techniques as characterization methods are considered. Currently, it becomes imperative to know the role of the Al2Cu against the susceptibility to corrosion of these alloys.The present work aims to studying the electrochemical behavior of aluminum base alloys with the following compositions: Al1wt.%Cu, Al15wt.%Cu and Al33.2wt.%Cu (with different grain structures), in 1M NaCl solution, at room temperature. Cyclic potentiodynamic polarization tests were performed and were found that the alloys with more than 1wt.%Cu in the matrix have an unstable behaviour and without tendency to reach passivity. The equivalent circuits derived from electrochemical impedance spectroscopy technique (EIS) generally showed two capacitive contributions. The susceptibility to corrosion becomes a complex function, not only of copper concentration and structure, but also with interdendritic spacings and distribution of phases in the alloys.