Phase Transition Behaviour of Tricalcium Phosphate (TCP) Doped with MgO and TiO2 as Additives

Abstract

In this study, the tricalcium phosphate [β-Ca3(PO4)2] behaviour using MgO and TiO2, respectively as additives has been investigated. The introduction of these additives is to control the phase transition of TCP during thermal process. The tricalcium phosphate (β,α) phases change when the temperature of sintering increase and/or during cooling down. To investigate the phase transition we examined tricalcium phosphate powder doped using 5 mol % of MgO or TiO2. The β-TCP and additives powders were mixture with acetone and dried using rota-vapour to eliminate all the solvent at 45°C for 3 h. After this procedure the powders were uniaxially pressed at 50 MPa and sintered in air-atmosphere at 1100°C to 1200°C for 5 h. All the sintered compacts were measurements by relative density, porosity, shrinkage, shrinkage rate, and the polished and fracture surfaces were investigated using a scanning electron microscope (SEM). To verify the transition phase the differential thermal analysis (DTA) and X-ray diffraction studies were carried out. The experimental results of relative density showed 92 % (MgO) and 90 % (TiO2) at 1200°C.