The damage accumulation mechanism of Ti-6Al-4V alloy under simultaneous corrosion and fatigue was studied. Corrosion fatigue characteristics of the alloy were evaluated by using newly developed corrosion-fatigue system, with special attention to synergetic effects of corrosion and fatigue on repassivation behavior. Two types of corrosion fatigue tests, potentiostatic polarization test with fatigue damage and free corrosion potential measurement test with simulataneous application of fatigue were carried out. In corrosion fatigue test, the electric current density increased as the frequency of fatigue became higher. This is caused by surface corrosion reaction occurred with development of cracks. However, the number of cycle to failure did not change with the frequency of fatigue. Therefore, it was shown that fatigue does not influence the corrosion fatigue damage. It was also shown that titanium alloy was superior in corrosion resistance.
