Abstract:A composite ceramic coating containing B4C and TiO2 with excellent wear resistance and corrosion resistance was formed on the pure Ti via micro-arc oxidation. The influence of the concentration of B4C particles added into electrolyte on the microstructure, phase composition, adhesion, wear resistance and corrosion resistance of the coatings was investigated. The results show that TiO2-B4C composite coatings consisting of rutile TiO2, anatase TiO2 and B4C phases were more uniform and denser than TiO2 coating. With the increase of B4C particle concentration, the adhesion, the wear resistance and corrosion resistance of the coatings increased firstly and then decreased. TiO2-0.9B4C coating displayed strongest adhesion of 22.6 N due to the most compact microstructure. TiO2-0.9B4C coating exhibited the best wear resistance. Its breakage time was 19.24 min and its wear width was 384.53 μm. The wear mechanisms were abrasive wear and fatigue wear. TiO2-0.9 B4C coating showed the best corrosion resistance. The self-corrosion potential, corrosion current density and polarization resistance of the coating were -213.38 mV, 5.47×104 Ω?cm2 and 2.37×10-6 A?cm2, respectively. According to the Bode-phase diagram, it can be speculated that the coatings were composed of two oxide layers, a porous outer layer and a dense inner layer.