ELECTROCHEMICAL AND SPONTANEOUS PASSIVATION OF THE CoCr ALLOY AS CORROSION PROTECTION

The aim of this work was to compare the level of protection of spontaneous and electrochemical passivation of the CoCr alloy against corrosion in environment simulating the conditions prevailing in the mouth.Passivation layer was obtained as spontaneous in air at 23 °C for 1 and 24 hours and by electrochemical method by polarization at potentials 0 and 100 mV for 1 and 24 hours. The corrosion resistance tests was realized by potentiodynamic method in Fusayamya saliva solution. Based on realized research it was concluded that electrochemical passivation better protects material from corrosion than passivation in air; extending the electrochemical passivation time results in greater corrosion resistance and higher passivation potential and longer time was related to formation of a thicker protective layer on the material's surface.