Novel mechanism to improve toughness of the hydroxyapatite bioceramics using high-frequency induction heat sintering

Novel technique was introduced to improve fracture toughness of hydroxyapatite (HAp) bioceramics. Composites of HAp/NiO with 1–5 wt% of electrospun NiO nanofibers were synthesized by wet-milling technique and the mixtures were consolidated rapidly to full density by high-frequency induction heat sintering (HFIHS). Effect of electrospun NiO nanofibers content on the toughness, hardness and microstructure properties was studied. The resulting composites showed good sintering behaviors, high toughness and hardness. Compared with the toughness of pure HAp, the heat sintered HAp/NiO nanofiber composites showed 200% increase in the toughness by the addition of 5 wt% NiO nanofibers. This can be related to the homogeneous dispersion of NiO nanoparticles in HAp at nanometer scales.