Title

SELF-ACTIVATION BEHAVIOR OF TITANIUM IN AQUEOUS SOLUTIONS OF ACIDS

Authorship

HWANG, WOON SUK

HWANG, WOON SUK

I am this author

DOI

10.5151/2594-5327-49v11-41-48

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Abstract

The stability of anodically passivated titanium in sulfuric and hydrochloric acid solutions was investigated by observing the self-activation behavior and galvanostatic cathodic reduction tests. It is appeared that applied cathodic current up to 0.2 μAcm⁻² is consumed almost entirely for reduction of passive film during activation process, and applied cathodic current is proportional to the reciprocal of activation time. From this linear relationship, two kinetic parameters, i.e. the amount of the charge reduced during the self-activation, q₀, and the rate of the self-activation process, i₀, were obtained, which is helpful to evaluate the stability of passive film. i₀ is decreased with increasing the passivation potential, passivation time and pH of solution. However, q₀ is independent on the passivation time and pH, and is proportional to the passivation potential. The stability of passivated titanium is increased in accordance with increasing the value of q₀ and decreasing i₀. It is discussed that i₀ is the parameter of representing the amount of defect on the passive film and q₀, representing the thickness and quantity of passive film.

Keywords

titanium, passivation, self-activation, passive film, acid solution