Effect of electrochemical state on corrosion–wear behaviors of TC4 alloy in artificial seawater

Abstract

The electrochemical and corrosion–wear behaviors of TC4 alloy in artificial seawater were studied. And the influences of electrochemical state on passive behavior, failure mechanism of passive film and corrosion–wear synergy were emphatically analyzed. The corrosion–wear analysis of the alloy was fulfilled by methods of mass loss, electrochemical testing and scanning electron microscope (SEM). It can be observed that the cathodic shift of open circuit potential and three order of magnitude increase of current density can be obtained during corrosion–wear process. Total corrosion–wear loss increases with increasing applied potential, confirming the synergy between wear and corrosion. High polarisation potential results in low coefficient of friction and high corrosion rate. The relative contribution of pure mechanical wear to total material loss deceases obviously with the increase of potential from open circuit potential to 0.9 V during corrosion–wear. Contributions of wear-induced-corrosion and corrosion-induced-wear are significant especially at higher potentials.