Preparation and corrosion resistance of graphite/titanium oxide composite coating

Abstract

AbstractGraphite/titanium oxide composite anti-corrosion coating was applied on the surface of aluminum alloy. The surface morphology and composition of the coating were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrochemical properties of the coatings with different graphite additions were tested by potentiodynamic polarization curves and AC impedance. The coatings with five graphite content were prepared. The phases in the coatings are stable before and after corrosion, avoiding the volume change caused by structural transformation, so that these coatings have good adhesion and are not easy to fall off from the metal surface. As a filler, the graphite dispersed in the coatings extends the penetration path of the corrosive medium. The electrochemical analysis showed that the physical barrier effect of the coating was enhanced with the increase of graphite content, and the optimal addition amount was 2.5%. When the content of graphite exceeds this value, the barrier effect of the coating on the corrosion medium will be weakened due to particle agglomeration.