Synthesis of biphasic ceramics of hydroxyapatite and β-tricalcium phosphate with controlled phase content and porosity

Biphasic porous ceramics of hydroxyapatite and beta-tricalcium phosphate have been prepared. The process was based on solid state reactions of brushite with calcium carbonate. The optimum heat treatment conditions for producing pure stoichiometric HA, beta-TCP and a biphasic composite of HA and beta-TCP with definite phase composition were identified by the methods of thermal analysis, X-ray diffraction and IR absorption spectroscopy. As a gas-forming agent, a certain amount of uncalcined powder was mixed with the corresponding precalcined powder to produce porous ceramics with different microporosities. Foam ceramics with macropores have been prepared by a dipping technique. The pore structure was examined using scanning electron microscopy.