Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10628518 | Corrosion Science | 2005 | 12 Pages |
Abstract
The corrosion protection afforded by a cerium conversion coating, formed by immersion in a solution containing rare earth salt and hydrogen peroxide, on pure magnesium and two magnesium alloys, AZ91 and AM50, has been studied. The effect of HCl pre-treatments on the morphology and on the corrosion resistance of the cerium conversion layer was investigated. A thicker and more homogeneous distribution of the conversion coating was obtained when the sample surface was pre-treated with acid. Higher amounts of cerium on the surface of the pre-treated samples were detected. The cerium conversion coating increased the corrosion resistance of the alloys because it ennobled the corrosion potential and decreased both the anodic and cathodic current. The acid pre-treatment further increased the corrosion resistance of the coated alloys. After five days of immersion in chloride environment the untreated samples showed localized corrosion while the chemical conversion coated samples appeared unaffected.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Katya Brunelli, Manuele Dabalà , Irene Calliari, Maurizio Magrini,