Material processing of a new calcium silicophosphate ceramic

The aim of this investigation was the synthesis of a new calcium silicophosphate ceramic by a powder metallurgy method combined with homogenization and heat treatment procedures. The chemical formulation and heat treatment temperatures were carefully selected bearing in mind information provided by the Ca2SiO4-7CaOP2O52SiO2 subsystem existing within the binary system of Ca3(PO4)2-Ca2SiO4. A single phase with a Ca2SiO4/Ca3(PO4)2 M ratio equal to 2/1 was synthetized from γ-dicalcium silicate and β-tricalcium phosphate previously synthetized. The reaction sintering process was followed by X-ray diffraction and Differential Thermal Analysis. The obtained ceramic was characterized by X-ray diffraction, micro-Raman and scanning electron microscopy with attached wavelength dispersive spectroscopy. At the light of the results a two-step synthesis conditions was used: heating at 1550 °C/3 h then liquid-nitrogen was quenched, ground and pressed; secondly, heating at 1300 °C/3 h and subsequent annealing at 1200 °C for 24 h.