The composition of the passive film on Ti-15Mo alloy, formed in 1 mol]L and 4mol/L HCI and 2 mol/L H2SO 4 solutions at 70 *C (160 OF) under anodic polarization is investigated by XPS and electrochemical techniques. Anodic polarization potential is found to have an obvious influence on the content of Mo in the film. At lower anodic polarization potentials, the surface of the passive film is enriched in Mo. However, at higher anodic polarization potentials, the surface is diluted in Mo. The anions of the electrolytes influence the composition of the passive film. In HCI solution, chloride ions are incorporated with the passive film during its formation. The passive film consists of a compound containing chloride and oxide ions. While in H2SO 4 solution, the passive film only consists of titanium-molybdenum oxide. Sulfide ions and other sulfur are not incorporated. Ti-Mo alloys have a better passivity than pure Ti in HC! and H2SO 4 solutions. This passivity is related to the enrichment of Mo in the surface of the passive film.

A new type of sacrificial coating (named SA coating) was developed by adopting anodic pigment of aluminum based alloy powder to make the underlying metal more negative than its corrosion potential. The effects of the Pigment Volume Concentration (PVC) on corrosion protection for the substrate metal were studied by potential monitoring, AC impedance measurement, salt water immersion, and routine tests. Optimum pigment volume concentration range was determined to provide satisfactory corrosion protection and the protective mechanisms were proposed to explain the experimental results.Ein neuer Typ von galvanisch wirkender Beschichtung (SA Beschichtung) wurde auf der Basis eines anodischen Pigments aus einem Aluminiumlegierungspulver entwickelt, wobei das Potential des darunterliegenden Metalls unterhalb seines freien Korrosionspotentials verschoben wird. Der EinfluS der Pigmentvolumenkonzentration (PVC) auf den Korrosionsschutz des Substratmetalls wurde mittels Potentialmessung, AC Impedanzmessung, Salzwassertauchversuchen und Routinetests untersucht. Urn einen ausreichenden Korrosionsschutz zu gewahrleisten, wurde ein optimaler Bereich der Volumenkonzentration des Pigments ermittelt. Schutzmechanismen, die die experimentellen Ergebnisse erklaren, werden vorgeschlagen.