Influence of Hydrothermal Processing Parameters on Phase Stability of Hydroxyapatite

Abstract:

Nanosized hydroxyapatite(HAp) was synthesized hydrothermally and influence of processing parameters, such as reaction temperature and time, pH, and Ca/P ratio, on the phase stability of HAp was evaluated after pressureless sintering at 1250°C in air. The highest stability was achieved from the powder obtained at a processing condition for the lowest solubility of Ca2+, which corresponds to temperature close to 200°C, time <4h, pH>9.0, and Ca/P = 1.67. The stability of nanosized HAp in HAp/3Y-TZP composites was slightly inferior to commercial one, but the involvement of hydrothermally synthesized HAp improved sintered density of the composites and stability of t-ZrO2 phase in the composites.