Improvement of pore orientation and mechanical properties for hydroxyapatite – alumina composite porous scaffolds

Abstract

A novel composite porous scaffold of hydroxyapatite (HA) and alumina was fabricated using the gelation freezing method. First, the microstructure was observed using scanning electron microscopy. The addition of alumina to HA led to an improved pore orientation attributed to the improved latent heat release during the freezing process owing to its higher thermal conductivity. The appropriate sintering temperature for composites consisting of different ceramics, HA, and alumina exceeded 1450 °C. Next, a compression test was conducted with fracture behavior monitoring using an acoustic emission method. The proposed HA-alumina composite porous scaffold exhibited better mechanical properties with higher porosity compared to scaffolds with randomly oriented pores. Furthermore, it was observed that the alumina addition and sintering temperature affected the macrofracture and microfracture behaviors, respectively.