Corrosion protection of magnesium alloy AZ31 sheets by spin coating process with poly(ether imide) [PEI]

In the present study, the potential of poly(ether imide) as corrosion protective coating for magnesium alloys was evaluated using the spin coating technique. The influence of different parameters on the coating properties was evaluated and the corrosion behaviour of the coatings was investigated using electrochemical impedance spectroscopy. The best corrosion protection was obtained preparing the coatings under N-2 atmosphere, using 15 wt.% solution in N'N'-dimethylacetamide (DMAc) which resulted in a coating of approximately 2 mu m thickness, with an initial impedance of 10(9) Omega cm(2) and of 10(5) Omega cm(2) after 240 h of exposure to a 3.5% NaCl solution. (C) 2010 Elsevier Ltd. All rights reserved.