Surface modification of pure titanium treated with B4C at high temperature

A solid diffusion method was employed to modify the surface of commercial pure titanium in this paper. The thermodynamics and the reactive process were analyzed. And the performance of the modified surface was also examined. The modified surface of pure titanium was covered with a compound layer of TiC, TiB and TiB2. The thickness of the compound layer was about 400 μm. The formation of the compounds is thermodynamically and kinetically feasible at the temperature of 1000 °C. The surface corrosion resistance in a 2% HF solution was improved greatly. The Vickers microhardness of the modified surface reached 820HV, which was much higher compared with the hardness of the original titanium substrate of 180HV. The surface shows a hardness gradient according to the concentration distribution of carbon and boron atoms.