LAUSR

Earlier, it was shown that titanium in phosphoric-acid solutions has a restricted corrosion resistance. The aim of our investigation is to study the electrochemical behavior of pressed porous titanium structures in phosphoric acid in the presence of ions of heavy metals. By using the volumetric and potentiometric methods and the method of cyclic voltammetry, we investigate the electrochemical processes on the surface of porous titanium electrodes in solutions of phosphoric acid. The addition of surface-active organic compounds with sulfur- and nitrogen-containing groups only insignificantly delays the onset of the corrosion process, which reveals a low efficiency of the organic corrosion inhibitors for titanium. It is demonstrated that Cu2+ -ions can be effective inhibitors for porous titanium structures. In addition to the blocking effect copper forms an independent phase and may play the role of cathodic additive. The overvoltage of hydrogen release for copper is much lower than for titanium, which facilitates the cathodic process and results in a shift of the potential of corrosion couple into the zone of passivation of titanium.