Mechanical properties of fully porous and porous-surfaced Ti–6Al–4V implants fabricated by electro-discharge-sintering

Twelve different porous implant compacts were fabricated by electro-discharge-sintering (EDS) of atomized spherical Ti–6Al–4V powders using single pulses of 0.75–2.0 kJ/0.7 g-powder, from 150, 300, and 450 μF capacitors. The solid core formed in the center of the compact after discharge was composed of acicular α + β Widmanstätten grains and the porous layer consisted of particles connected in three dimensions by necks. The hardness value at the solid core was much higher than that at the particle interface or at particles in the porous layer. This can be attributed to both heat treatment and work hardening effects induced from the EDS. The compressive yield strength was in a range of 19–436 MPa and significantly depended on both input energy and capacitance. Selected porous-surfaced Ti–6Al–4V implant compacts with a solid core have much higher compressive strengths compared to human teeth and sintered implants.