CrVI free primer: from corrosion findings to profile

Up to now, protection of aircraft structures is achieved by a multilayer system that includes, in general, a porous oxide or a conversion coating, a chromated primer and a top coat. Each layer plays a role in the protection scheme and key factor is addressed by specifications. As environmental concern is a strong driving force, the replacement of hexavalent chromium in paint is considered by all aerospace manufacturers as a risky target to achieve in the next future. The two key paint film properties, adhesion with respect to interfacial failure and transient stress state, and leachability of inhibitors, are discussed in order to propose a profile for the new generation of CF primer capable to meet the requirements of aeronautic technical specifications.