Effect of spark plasma sintering temperature on the pore characteristics, porosity and compression strength of porous titanium foams

In this work, porous titanium (Ti) foams were successfully produced using spark plasma sintering technique at four different temperatures (up to 650 degrees C), in conjunction with vacuum sintering (used as a post-treatment) at a constant temperature of 1200 degrees C. To obtain a porous structure, 60 vol% of sodium chloride was included as a pore spacer, with the addition of polyethylene glycol solution for Ti-NaCl interparticle binding. The work aimed at studying the effect of sintering temperature on the final pore features and compression resistance of the porous titanium foams. X-ray diffraction and scanning electron microscopy as characterization techniques were used to analyze phases and pore evolutions, respectively. The results showed that the pore characteristics and the final porosity of porous titanium foams profoundly depend on the sintering temperature. The lowest porosity of approximately 53.9 vol%, with denser pore walls, was seen at the highest sintering temperature. Such foams sintered at 650 degrees C can resist the compression stress as high as 123 MPa while exhibiting the stiffness value of 8.1 GPa. The results indicate that the porous Ti foams produced have great potential for applications in hard tissue engineering.