Study on the structure and corrosion resistance of micro-arc oxidation coatings on TA10 titanium alloy with different graphite additions

Abstract

To improve the corrosion resistance of the Ti–0.3Mo–0.8Ni (TA10) titanium alloy, a micro-arc oxidation coating was prepared on its surface, and the effect of different amounts of graphite addition on the structure and corrosion resistance of the coatings was studied. Through methods such as X-ray diffraction phase analysis, microscopic morphology analysis, roughness analysis, coating thickness analysis and hardness testing, it was found that the added graphite particles can react with silicon (Si) in the electrolyte to promote the formation of the silicon carbide (SiC) phase, thereby improving the surface morphology of the coatings, increasing the thickness of the coatings and improving the microhardness of the coatings. At the same time, dynamic potential polarization curve and scanning electrochemical test results show that the formation of the silicon carbide phase can increase self-corrosion potential and reduce self-corrosion current density. When the amount of graphite added is 1.0 g/l, the self-corrosion potential and self-corrosion current density are −0.129 V and 2.9 × 10 −8 A/cm 2 , respectively. This indicates that adding graphite particles can enhance the corrosion resistance of the TA10 titanium alloy.