THE EFFECT OF FILM FORMATION TEMPERATURE ON THE STOCHASTIC-PROCESSES OF PIT GENERATION ON ANODIZED TITANIUM

The anodic oxide films on titanium were formed potentiostatically in 0.5 M H2SO4 solution at various temperatures ranging from 303 to 363 K. The effect of film formation temperature on the pit generation on anodized titanium was investigated in 2 M NaBr solution by the stochastic approach. The distribution of pitting potential approximately follows the normal probability distribution and the pit generation process occurs in accordance with the parallel birth and death stochastic model. The pitting potential increases significantly above 343 K due to the decrease in the pit generation rate and to the increase in the pit repassivation rate. The dependence of the pitting potential on film formation temperature can be explained by the change in the properties of the film.