Enhancement of the electrochemical corrosion resistance of Ti6Al4V alloy reinforced by nano- and micro-TiC particles through directed energy deposition

Nano- and micro-size TiC ceramic particles were synergistically utilized for the reinforcement of Ti6Al4V alloy, manufactured through directed energy deposition. The corrosion current density of nano/micro-TiC/Ti6Al4V composite decreased by 23.7% and 74.6% compared to Ti6Al4V composites containing only TiC microparticles or only TiC nanoparticles, and by 77.8% compared to pure Ti6Al4V. A stable passive film of TiO2 with higher content of bound water is formed in nano/micro-TiC/Ti6Al4V composite specimen. The excellent electrochemical corrosion resistance of the nano/micro-TiC/Ti6Al4V composite is attributed to the α martensite transformation and the accumulation of [TiCl6]2- complexes, which promotes the formation of TiO2 passive film.