Characterization of Corrosion Protective Films on Steel and Aluminum Alloys

Coatings for corrosion prevention based on rare earths

“…Early work by Mansfeld developed alternating CeCl 3 , and Ce(NO 3 ) 3 treatments followed by, or interrupted with a polarization step in NaMo O 4 . 154,167,168,170,172,175,176 Kendig and Thomas 177 found that Ce and MoO 4 2− played synergistic roles in the protection of the aluminium suggesting that the cerium was not an active player in self-healing of the fi lm, but the molybdate did have a role, as free MoO 4 2− ion was available for self-repair. Later studies showed that the fi lm developed using this process resulted in cerium products depositing onto the cathodes and Ce(MoO 4 ) 2 particles developing in the surface of the coating.…”

“…Other bodies of work in this area include the work of Mansfeld and co-workers, 154,[167][168][169][170][171][172] as well as those of Botana, Abelle, Bethencourt and co-workers 68,102,173,174 who developed boehmite-like coatings on the matrix of alloys using conversion coating solutions containing cerium nitrate. It is diffi cult to draw general conclusions from the literature in this area as a variety of pretreatments are used.…”