|
authors |
Lamaka, SV; Montemor, MF; Galio, AF; Zheludkevich, ML; Trindade, C; Dick, LF; Ferreira, MGS |
|
nationality |
International |
|
journal |
ELECTROCHIMICA ACTA |
|
author keywords |
sol-gel coating; magnesium alloy; AZ31 B; corrosion; EIS |
|
keywords |
ELECTROCHEMICAL TEST METHODS; EVALUATING ORGANIC COATINGS; TEST PARAMETER MEASUREMENTS; IMPEDANCE SPECTROSCOPY; GALVANIZED STEEL; ALUMINUM-ALLOYS; METALS; PRETREATMENTS; UPDATE; NANOCONTAINERS |
|
abstract |
This work aims to develop and study new anticorrosion films for AZ31B magnesium alloy based on the sol-gel coating approach. Hybrid organic-inorganic sols were synthesized by copolymerization of epoxy-siloxane and titanium or zirconium alkoxides. Tris(trimethylsilyl) phosphate was also used as additive to confer additional corrosion protection to magnesium-based alloy. A sol-gel coating, about 5-mu m thick, shows good adhesion to the metal substrate and prevents corrosion attack in 0.005 M NaCl Solution for 2 weeks. The sol-gel coating system doped with tris(trimethylsilyl)-phosphate revealed improved corrosion protection of the magnesium alloy due to formation of hydrolytically stable Mg-O-P chemical bonds. The structure and the thickness of the solgel film were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The corrosion behaviour of AZ31B substrates pre-treated with the sol-gel derived hybrid coatings was tested by electrochemical impedance spectroscopy (EIS). The chemical composition of the silylphosphate-containing sol-gel film at different depths was investigated by X-ray photoelectron spectroscopy (XPS) with depth profiling. (C) 2008 Elsevier Ltd. All rights reserved. |
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publisher |
PERGAMON-ELSEVIER SCIENCE LTD |
|
issn |
0013-4686 |
|
year published |
2008 |
|
volume |
53 |
|
issue |
14 |
|
beginning page |
4773 |
|
ending page |
4783 |
|
digital object identifier (doi) |
10.1016/j.electacta.2008.02.015 |
|
web of science category |
Electrochemistry |
|
subject category |
Electrochemistry |
|
unique article identifier |
WOS:000255604900024
|
