Corrosion‐resistant coatings: a nanotechnology approach

The corrosion performance of ceramic films of SiO2‐Al2O3 prepared by the sol‐gel processing of organometallic compounds and deposited by dip‐coating technique on 1008 steel foils has been evaluated. Two kinds of procedures were developed to produce the sol‐gel coatings. The influence of the coatings on the chemical corrosion of the substrate has been measured by using potentiodynamical polarization curves in 0.5 M H2SO4 and 1 M HCl solutions at room temperature. Sol‐B showed the best behaviour in protective corrosion, in addition to the fact that the number of applications does not influence the resistant corrosion. Protection of coatings was limited by the growing of film cracking due to residual stress between coating and substrate. The results were supplemented by SEM analysis.