Bioactive Hydroxyapatite/Calcium Silicate Composites Obtained by Fast Hot Pressing: Structure and Flexural Strength
The present work deals with the preparation and characterization of ceramic composites for the substitution of load-bearing bone portions, made of hydroxyapatite (HA) and bioactive β- calcium silicate (β-Ca2SiO4) as a reinforcing phase. The composite materials were prepared by Fast Hot-Pressing technique (FHP), which allowed the rapid sintering of monolithic ceramics at temperatures up to 1500 °C, well above the commonly adopted temperatures for sintering of hydroxyapatite (1200-1300 °C), in order to achieve the densification of the reinforcing phase also. XRD analysis reported no formation of secondary phases other than HA and β-Ca2SiO4, after FHP cycles. Flexural strength tests were performed on selected samples sintered at different temperatures: the composite materials exhibited increased mechanical resistance compared to samples constituted of HA only. These preliminary results confirmed that composites of HA and β- Ca2SiO4 are promising for the development of bioactive load-bearing ceramic bone substitutes.
Guy Daculsi and Pierre Layrolle
S. Sprio et al., "Bioactive Hydroxyapatite/Calcium Silicate Composites Obtained by Fast Hot Pressing: Structure and Flexural Strength", Key Engineering Materials, Vols. 361-363, pp. 423-426, 2008