Sol-gel routes to replace chromate based treatments for protection against zinc corrosion

Regarding the environmental consciousness and requirements relative to industrial processes, researchers and end users have to move to more green surface treatments. That is why, the use of toxic compounds such as chromates must be strictly prohibited. So, in order to replace this element preserving an efficient protection against corrosion of metals, a new route using sol-gel process clearly appears as a promising alternative method. In this paper, we investigated three different sol-gel systems in various media (alcohol and/or water) and compared their efficiency in terms of protection against corrosion and environmentally friendliness. Thus, industrial normalized corrosion test and electrochemical analyses such as polarisation curves and EIS measurements were carried out in order to both evaluate and discuss coatings behaviour in corrosive environment.