Papers by Keyword: Density Strength

Abstract: This paper reports the influence of aging time and reaction temperature on the surface morphology and mechanical properties of hydroxyapatite (HA) synthesized by a hydrothermal method. Calcium nitrate and ammonium orthophosphate solutions were premixed and fed to an autoclave and reacted to temperatures varying between 25-250°C for 2-10 h. Results indicate the strong positive influence of reaction temperature on the HA particle aspect ratio. The density of the discs pressed from these samples reached 85-90% of the theoretical density after calcination at 1200°C for 1 h. Sintered density and flexural strength were found to increase with increasing aging time and reaction temperature. A maximum flexural strength of 78 MPa was observed for the sample synthesized at 170°C for 5 h with the predicted average at these conditions being 65 MPa.