Kinetics and sintering mechanisms of hydro-thermally obtained hydroxyapatite

In this paper, the kinetics and sintering mechanism of hydro-thermally synthesized hydroxyapatite in the temperature range 900–1100 °C are presented. It was found that at 900 °C, the sintering process is very slow, whereas at 1000, 1050, and 1100 °C is much faster, caused by activated sintering with liquid phase/phase of solution on spots with concentrated material impurity and the formation of reaction/polyeutectic mixtures dominates. The activation energies of sintering were also determined. At all the investigated sintering temperatures, an approximate value of 90 kJ mol−1 was found.