Mechanical behaviors of porous Ti with high porosity and large pore size prepared by one-step spark plasma sintering technique

Porous Ti with 38-56% porosity and 50-500 μm pore size was prepared by one-step spark plasma sintering (SPS) method using modified mold combined with space holder (ammonium hydrogen carbonate, NH4HCO3) technique. Pore characteristics and mechanical behaviors of porous Ti were investigated by varying sintering temperatures (1000-1200 °C). Results showed that porous Ti prepared by SPS had large plasticity and the compressive cyclic stress-strain curves showed nonlinear recovery and hysteresis effect. With the sintering temperature increasing, smooth and dense pore walls, and relatively isotropic pore surface of porous Ti were obtained, the elastic modulus and compressive strength increased. The recoverable strain ratio of porous Ti after five cycles could reach more than 70% at the pre-strain of 2%. When temperature was 1200 °C, the good combination of interconnected pore characteristics, proper elastic modules (11.2 GPa, close to that of human bones), higher compressive strength (287 MPa) and stable recoverable behaviors of porous Ti, made this material possible to be used for load-bearing hard tissue implants.