Rare-earth modified coatings on 2024 aluminum alloy were prepared by sol-gel methods,
aiming at improving the corrosion resistance with the environmental friendly features. The
investigation put emphases on the effects of rare-earth additives on corrosion resistance and
microstructure of sol-gel coatings. The results revealed that coated samples containing 2g·L-1
rare-earth not only delayed the incubation period of corrosion, but also hindered the development of
it, and their corrosion rate decreased 80.3% compared with the bare ones and was 15.9% than the
rare-earth free coated ones. The action of rare-earth on morphology and microstructure of sol-gel
coatings for 2024 Al alloy was studied by SEM. High density good cohesion, and intact coverage
were showed clearly ,which provided a reliable proof of the reformative effects of rare-earth
additives.