This research investigates the tendency of recent aluminium alloys (AA2198 and AA2139) to attain a stable passive condition in aerated neutral electrolyte solutions and compare their behaviour with that of a common 2xxx aluminium alloy (AA2024). Corrosion potential evolutions, fast and slow potentiodynamic polarization curves and impedance testes were carried out for these alloys in diluted, aerated sodium sul-phate and sodium chloride solutions. At the beginning of the immersion the values of their corrosion potentials can be re-lated to the different alloy composition (i.e. the presence of Li and Cu content), while, at long testing times, to the pitting tendency, which depends on the different amounts of intermetallic dispersoids between AA2198 and AA2139.
POLARIZATION BEHAVIOUR OF NEW ALUMINIUM ALLOYS (AA2139 and AA2198) IN NEUTRAL MEDIA
BALBO, Andrea;GRASSI, Vincenzo;FRIGNANI, Alessandro;ZUCCHI, Fabrizio
2014
Abstract
This research investigates the tendency of recent aluminium alloys (AA2198 and AA2139) to attain a stable passive condition in aerated neutral electrolyte solutions and compare their behaviour with that of a common 2xxx aluminium alloy (AA2024). Corrosion potential evolutions, fast and slow potentiodynamic polarization curves and impedance testes were carried out for these alloys in diluted, aerated sodium sul-phate and sodium chloride solutions. At the beginning of the immersion the values of their corrosion potentials can be re-lated to the different alloy composition (i.e. the presence of Li and Cu content), while, at long testing times, to the pitting tendency, which depends on the different amounts of intermetallic dispersoids between AA2198 and AA2139.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
