info:eu-repo/semantics/article
Corrosion Resistance of Aluminum-Copper Alloys with Different Grain Structures
Fecha
2020-11Registro en:
Roman, Alejandra Silvina; Mendez, Claudia Marcela; Gervasi, Claudio; Rebak, Raúl B.; Ares, Alicia Esther; Corrosion Resistance of Aluminum-Copper Alloys with Different Grain Structures; Springer; Journal of Materials Engineering and Performance; 30; 1; 11-2020; 131-144
1059-9495
1059-9495
CONICET Digital
CONICET
Autor
Roman, Alejandra Silvina
Mendez, Claudia Marcela
Gervasi, Claudio
Rebak, Raúl B.
Ares, Alicia Esther
Resumen
Electrochemical studies and microstructure analysis of directionally solidified hypoeutectic and eutectic aluminum-copper alloys were performed. Optical and scanning electron microscopy studies of corroded specimens with columnar and equiaxed microstructures in 0.1 M, 0.5 M, and 1 M NaCl solutions were conducted. Low-rate potential scanning and alternating current (AC) electrode impedance measurements were conducted to study the corrosion resistance of four aluminum-copper alloys. The concentration of Cu in the alloys proved to be a key factor in the corrosion resistance of the Al-Cu alloys, which controlled the fraction of α and θ phases and the morphological distribution of these phases. The addition of Cu provides cathodic sites that increase adjacent anodic activity and higher corrosion susceptibility of the Al-Cu alloys, as compared with pure Al. Arise in the Cu amount that is linked to an increased concentration of the Al2Cu intermetallic or theta phase results in a higher susceptibility to corrosion for the studied alloys. A microstructural morphology related to a decreased area of contact between the α-phase and the Al2Cu intermetallic phase enhances the corrosion resistance of the Al-Cu alloys. For the Al-1wt.%Cu alloy increasing the content of Cl− produces a beneficial result related to a more resistive passive film. For the rest of the studied alloys with nobler corrosion potentials, the increase in Cl− results in a decrease in their corrosion resistance.