Phase evolution of hydroxyapatite nanocomposites during sintering

Decomposition of hydroxyapatit strongly affects its mechanical and biological properties. The present work was based on Le Chatelier’s principle which dictates that the presence of water vapour should impede the release of water vapour from hydroxyapatite, and thus suppresses the decomposition of hydroxyapatite to unhydrated calcium phosphate phases. After characterizing the first powders using X-ray diffraction technic (XRD) and scanning electron microscope (SEM), Pure hydroxyapatite, hydroxyapatite -20 wt% alumina and hydroxyapatite -20 wt% titanium mixtures were pressed and sintered in air, moist, and reduction atmospheres at 1200oC for 2 h. In order to study the phase and structural evolution, XRD was used. Phase investigation of sintered bodies showed that, pure hydroxyapatite is stable in all three atmospheres at 1200oC. But, moist and reduction atmospheres were preferred atmospheres to suppress the hydroxyapatite decomposition in hydroxyapatite -alumina and hydroxyapatite –titanium nanocomposites, respectively

کلیدواژه ها:

Hydroxyapatite ، decomposition ، Nanocomposite ، Atmosphere ، Phase transformation