**2.1 Preparation of ceramics**

To produce biocomposites, the synthesis of β-tricalcium phosphate powder was conducted by solid-state reaction from calcium carbonate (CaCO3) and calcium phosphate dibasic anhydrous (CaHPO4). Stoichiometric amounts of high purity powders such as CaCO3 (Fluka, purity ≥98.5%) and CaHPO4 (Fluka, purity ≥99%), were sintered at 1000°C for 20 h according to the reaction reported in Ref [18]. While Alumina and Titania used are of commercial origin. They are high purity powders (Riedel-de Haien, purity ≥99%).

It is worthwhile to note that the size of particles of the powder was (2.53 � 0.2 μm for Al2O3, 2.79 � 0.2 μm for β-TCP and 0.11 μm for TiO2).

The initial mixture was 90 wt% Al2O3 and 10 wt% TCP and was mixed with different amounts of TiO2 (1 wt.%, 2.5 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 7.5 wt.% and 10 wt.%). The mixtures were homogeneously mixed in an agate mortar and were milled in ethanol utilizing an ultrasound machine then dried for 24 h at 80°C to eliminate the ethanol and generate a finely divided powder. The dried powder was pressed in metallic mold depending on the geometry of the specimens and uniaxially pressed using LLOYD model test (machine LR50K) at 67 MPa.

Subsequently, those compacted samples of all the compositions were sintered at 1600°C for 60 min within a programmable muffle furnace (Vecstar furnace model XF5) and in normal atmospheric conditions. All specimens were heated at a rate of 10°C min�<sup>1</sup> and cooled at a rate 20°C min�<sup>1</sup> .

The densification of the sintered samples was evaluated from measurements of the dimensions of the samples and the relative error of the densification value was about 1%.
