The effects of MgO, ZrO2 and TiO2 as additives on microstructure and mechanical properties of Al2O3-Fap composite

Calcium phosphate ceramics such as, hydroxyapatite (Ca10(PO4)6(OH)2,Hap) and fluorapatite (Ca10(PO4)6F2,Fap), have been widely adopted as substitute materials for human bone and teeth, because of their excellent biocompatibility and their similarity in composition to bone mineral. This work assessed the effects of MgO, ZrO2 and TiO2 as additives during the densification of the Al2O3-26.5% Fap composites. In particular, it investigated the densification and the mechanical properties along with the elastic modulus of the sintered composites. The first finding of importance was that the addition of ZrO2 or MgO impaired the densification of those composites at the sintering temperature of 1500 °C. Nevertheless, titania, when added up to 1.4 wt%, was found to be a good effective additive in improving densification. Secondly, this study found that titania doping achieved 94% of the theoretical density and provided composites with a mechanical strength, a hardness and Young's modulus of 74 MPa, 684 Hv and 215 GPa, respectively. These findings can make of titania a good additive to Al2O3 and Fap to design a material that has useful applications in biomedical implantations.