Fabrication and characterization of core shell HA-n-ZrO₂ composite ceramic powders

Hydroxyapatite-zirconia composite powders were prepared using the hydrothermal-deposition in-situ stepwise reaction method. The XRD and TEM were employed to characterize the phase, morphology and size of the resulting powders. The composite ceramic samples were fabricated via moulding and thermal treatment of the composite powders. The results show that the as-synthesized powders with nanosize are composed of well-crystallized tetragonal phase ZrO₂ core clad with hydroxyapatite shells to fabricate the core-shell structure (HA-n-ZrO₂). With the increase of HA mass fraction from 0 to 100%, the as-clad HA shells get thicker gradually, but the bending strength and the mean Vickers hardness of the resulting ceramic samples moulded by the composite powders become lower from 183 MPa to 61 MPa and 781.75 MPa to 131.76 MPa, respectively.