RESUMEN
In this study, sintering effects on microstructural behavior of bovine derived hydroxyapatite doped with powder mullite are considered in the temperature range between 1000°C and 1300°C. Results show that maximum values of both compressive strength and microhardness are achieved in the samples sintered at 1200°C for all mullite additions of 5, 7.5, 10 and 12.5wt%. Moreover, above 1000°C, decomposition of HA and new phase formations such as whitlockite and gehlenite play a major role in both compressive strength and microhardness properties which increase up to 10wt% mullite reinforcement.
Asunto(s)
Durapatita/química , Silicatos de Aluminio , Animales , Bovinos , Fuerza Compresiva , Ensayo de Materiales , PolvosRESUMEN
The fabrication and characterization of bovine hydroxyapatite (BHA) and cerium oxide (CeO2) composites are presented. CeO2 (at varying concentrations 1, 5 and 10wt%) were added to calcinated BHA powder. The resulting mixtures were shaped into green cylindrical samples by powder pressing (350MPa) followed by sintering in air (1000-1300°C for 4h). Density, Vickers microhardness (HV), compression strength, scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were performed on the products. The sintering behavior, microstructural characteristics and mechanical properties were evaluated. Differences in the sintering temperature (for 1wt% CeO2 composites) between 1200 and 1300°C, show a 3.3% increase in the microhardness (564 and 582.75HV, respectively). Composites prepared at 1300°C demonstrate the greatest compression strength with comparable results for 5 and 10wt% CeO2 content (106 and 107MPa) which are significantly better than those for 1wt% and those that do not include any CeO2 (90 and below 60MPa, respectively). The results obtained suggest optimal parameters to be used in preparation of BHA and CeO2 composites, while also highlighting the potential of such materials in several biomedical engineering applications.