Ion Beam Analysis Investigation of Pit Nucleation on Titanium in Bromide Media

Abstract

Abstract Corrosion pit nucleation on titanium in bromide solutions was studied using ion beam analysis. At potentials lower than the potential of pit nucleation (Enp), Br− rich sites observed appear as repassivated metastable micropits. Clusters of Ti Br4 molecules should be the real pit nuclei. Stabilization, i.e., activation of micropits can only be obtained at higher potentials than Enp, as shown by the topographical agreement between the micropits and macropits grown afterwards. On titanium covered with stable passive film, blisters full of occluded gas are formed and the amorphous oxide passive film may break in preferential directions induced from areas enriched with crystallized bromide compounds.