PREPARATION OF ALPHA-TRICALCIUM AND BETA-TRICALCIUM PHOSPHATE CERAMICS, WITH AND WITHOUT MAGNESIUM ADDITION

Alpha- and beta-tricalcium phosphate (TCP) ceramics were prepared using various processing routes. The high-temperature limit of the stability domain of beta-TCP is increased by magnesium addition (up to 5 wt% of equivalent MgO). Impregnation of pre-sintered, porous skeletons of TCP with a Mg-containing solution is an easy way to prepare Mg-TCP. Mg-chloride and Mg-sulfate lead to anionic residues which can combine with TCP, whereas Mg-acetate and Mg-nitrate lead to materials free from anionic residues. Reaction-sintering of hydroxylapatite and dicalcium phosphate mixtures impregnated with a solution of either Mg-acetate or Mg-nitrate is, therefore, an interesting route for preparing Mg-TCP ceramics with a controlled alpha-to-beta ratio.