Improvement of the Corrosion Resistance of Aluminium Alloys Applying Diff erent Types of Silanes - Advanced Materials for Agriculture, Food and Environmental Safety - page 27

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Improvement of the Corrosion Resistance
of Aluminium Alloys Applying Dif erent
Types of Silanes
Anca-Iulia Stoica*, Norica Carmen Godja, Andje Stanković, Matthias Pölzler,
Erich Kny and Christoph Kleber
Centre of Electrochemical Surface Technology, Wiener Neustadt, Austria
Abstract
Due to their low density and good mechanical characteristics, aluminium alloys
are outstanding for use in aeronautics industry applications. Nevertheless, alloys
commonly used in aerospace, such as AA 2024, show higher corrosion rates than
pure aluminium and therefore need to be protected against corrosion attacks by
dif erent surface treatments. In the last decade, all novel studies concerning the
corrosion protection of aluminium and aluminium alloys were based on a “green
treatment,” indicating that silanes are one of the most promising alternatives for
chromates for the surface i nishing of Aluminium and Aluminium alloys.
Presented here are the results of a silane surface treatment based on water solu-
ble mixtures of silanes and alcohol soluble silanes which were used for the forma-
tion of corrosion protective coatings (conversion coatings) on the aluminium alloy
AA 2024. Also, the quality and performance of the sealed anodic i lms before and
at er a salt spray test (SST) are elucidated by the application of dif erent surface
sensitive techniques, such as electrochemical impedance spectroscopy (EIS), scan-
ning electron microscopy (SEM), focused ion beam (FIB), Fourier transformed
infrared spectroscopy (FTIR) and contact angle (CA) measurements.
Keywords: Aluminium, AA2024, TSA, silane, corrosion protection, SEM, FIB,
EIS, contact angle, SST