Microstructural and Mechanical Properties of Al2O3/HAp Composites for Use as Bone Substitute Material

This work involved the development of alumina/hydroxyapatite (Al₂O₃/HAp) composites for use as bone graft material in maxillofacial reconstruction. The effect of introducing 20 and 30 wt% of hydroxyapatite into the alumina matrix was also investigated. The composites were produced from hydroxyapatite synthesized by the precipitation method, using commercial alumina as a matrix. Samples of the composite material were compacted under 260 MPa of isostatic pressure, followed by sintering at 1200°C/2h and characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diametral compression. The XRD results confirmed the presence of Al₂O₃ and Ca₁₀(PO₄)₆(OH)₂ – HAp crystalline phases in all composites. The addition of HAp to the alumina matrix inhibited alumina grain growth, reducing intergranular porosity and thus promoting greater densification and mechanical strength of the composites.