Mechanical optimization of the composite biomaterial based on the tricalcium phosphate, titania and magnesium fluoride

The microstructure, the densification and the mechanical properties of the tricalcium phosphate - titania - MgF2 composites were investigated. The effect of MgF2 addition on the performances of the tricalcium phosphate - 40 wt% titania composites is discussed. The mechanical properties were investigated by Brazilian test, Vickers indentation and the ultrasound techniques. The mechanical properties of the tricalcium phosphate - 40 wt% titania composites reached optimum performances after the sintering process at 1200 °C for one hour with 4 wt% MgF2. Thus, the highest values of the rupture strength, Vickers hardness, Young׳s and the shear modulus reached 27 MPa, 360 Hv, 51 GPa and 20 GPa, respectively. The increase of the mechanical properties of the composites is due to the presence of the liquid phase and the formation of a new compound. Thus, the microstructure of the composites reveals the presence of a new lamella form relative to the Mg2(PO4)F. Beyond 4 wt% MgF2, the performances of the composites are hindered by the exaggerated grain growth and the formation of the bubbles.