Fabrication of porous Co-Cr-Mo compacts prepared by spark plasma sintering for biomedical applications

Porous Co-29Cr-6Mo (ASTM F75) compacts were fabricated by spark plasma sintering method (SPS) with plasma rotating electrode processed (PREPed) Co-29Mo-6Mo (mass%) powder with a diameter range (610-700 μm). The porosity of the compacts could be changed between 10.8% and 39.4% when the SPS temperature varies from 1023 K to 1273 K. Relatively large neck was formed by post annealing at 1473 K for 7.2 ks for the compacts containing the porosity of 32.4%, although the porosity change was only 0.6%, This annealing improves the bending strength of the compact. Young's modulus of the annealed compact containing the porosity of 31.4% shows 54.0 GPa, which is relatively higher than that of human cortical bone but approximately one-forth as much as that of as-cast Co-Cr-Mo alloy. The compact possesses the bending strength of 223.4 MPa, which is superior to that of human cortical bone.