Synthesis, sintering and microstructural characterization of nanocrystalline hydroxyapatite composites

Abstract

Nanocrystalline hydroxyapatite (HAp) exhibits better bioactivity and biocompatibility with enhanced mechanical properties compared to the microcrystalline counterpart. In the present work, nanocrystalline hydroxyapatite was synthesized by wet chemical method. Sintering was carried out with nanocrystalline alumina as additive, the content of alumina being varied from 10 to 30 wt% in the composite. For 20 and 30 wt % Al₂O₃, hydroxyapatite decomposed into tricalcium phosphate (TCP) above the sintering temperature of 1100°C. The fracture toughness of nano HAp-nano Al₂O₃ composite is anisotropic in nature and reached a maximum value of 6.9 MPa m^1/2.