Preparation And Microstruture Of ZrO₂-HA Biomedical Composite Ceramics

The synthesis of Hydroxyapatite powders and the fabrication process, microstructures and hardness of Zircinoa/Hydroxyapatite composite ceramics are studied.The powder of hydroxyapatite was synthesized by polyacrylamide gel method. The process was made by means of TG-DTA,FT-IR and XRD. Effects of process parameters on the properties of samples were discussed from the Ca/P ratio,pH values of the sol and the calcinating temperatures.The hydroxyapatite powder surface morphologies were characterized by TEM.The results show that hydroxyapatite powder could be synthesized on the conditions that pH values were between 2~3 and the calcinating temperature was 900℃.The average grain size of the powder was about 100nm and dispersed uniformly.Zircinoa/Hydroxyapatite composites were synthesized by the solid state method and liquid suspension method. Effects of process parameters on sintering properties of samples were discussed from the synthesis temperatures of powders and sintering temperatures. The compositions and surface morphology were characterized by XRD and SEM. The hardness was tested by HBV-30A. The relationships of fabrication process, composites, microstructures and hardness were discussed.SEM results show that the grains of the composite ceramics prepared by the two methods are different.XRD,FT-IR and EDS were employed to characterize the phase of the composites, and the result show that hydroxyapatite decomposed to calcium oxide andβ-TCP at 1250℃, Monoclinic phase zirconia appeared.And the composites mainly contain tetragpnal phase zirconia andβ-TCP as well as a bit of cubic phase zirconia and monoclinic phase zirconia.The results of hardness vs sintering temperatures,the content of hydroxyapatite and synthesis methods indicate that the sintering temperatures of composites, the content of hydroxyapatite and synthesis methods have great effects on the hardness of the composites.Hardness increases with the increase of the sintering temperatures and decresses with the contents of the hydroxyapatite.