Surface characteristics of porous titanium implants fabricated by environmental electro-discharge sintering of spherical Ti powders in a vacuum atmosphere

Abstract A single pulse of 1.5 kJ, from a 300 μF capacitor, was applied to 0.7 g of atomized spherical Ti powders to produce a porous-surfaced implant compact by environmental electro-discharge sintering (EEDS) in a low vacuum atmosphere. A solid core was formed by a discharge in the middle of the compact which is surrounded by a porous layer. Ti, C and O were the main constituents, with a smaller amount of N. The EEDS implant surface was lightly oxidized and was primarily in the form of TiO 2 . The lightly etched sample showed the surface form of metallic Ti, indicating that the EEDS breaks down the oxide film of the as-received Ti powder during the discharge process. However, a small amount of N in the form of nitride, which was also found in the as-received Ti powder, was not changed in its chemical state by EEDS.