Effect of temperature in process of sintering of hydroxyapatite powders

Samples of hydroxyapatite were synthesized by precipitation from aqueous solutions containing the precursor ions. The obtained precipitate was washed, dried, deagglomerated and sieved to obtain samples in powder form of homogeneous particle size. The material was sintered at different temperatures and subsequently characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, thermo-gravimetric and thermo-differential analyses and quantification of the specific surface area. Furthermore, porosity was determined using the Brunauer-Emmett-Teller and Barret-Joyner-Halenda methods, respectively. The powders showed changes in crystallinity, morphology and texture with increasing temperature. New phases were identified in the X-ray patterns due to decomposition of the material, corroborating other findings in the literature. Crystal growth and increased crystallinity were observed during heat treatments, while specific surface decreased, proving that the changes were due to the sintering processes.

hydroxyapatite; sintering; temperature; decomposition