Microstructure and mechanical properties of hydroxyapatite ceramics with zirconia dispersion prepared by post-sintering.

Hydroxyapatite ceramics with zirconia dispersion from fine powders synthesized hydrothermally were post-sintered at 1000-1300 degrees C under 200 MPa of argon for 1 h without capsules, after normal sintering in air at 1200 degrees C for 3 h. Densification was most significant with post-sintering at 1200 degrees C. Fracture toughness, Vickers hardness and elastic properties of these materials were investigated. Post-sintering gave twice the K1c value of transparent pure hydroxyapatite ceramics. Vickers hardness and Young's modulus of the ceramics were increased by post-sintering.