Aqueous gel-casting of hydroxyapatite

In the present work, an aqueous gel-casting of hydroxyapatite using a new polymeric system has been investigated. The effects of the dispersant, pH values on the dispersing ability of HA powder were studied and the rheological behavior of the slurries was investigated. The green body has a density of 1.621 g/cm3 and compressive strength as 32.6 ± 3.2 MPa. After pressureless sintering at 1250 °C for 2 h the relative density of the final product is about 96.7%. Bending strength, elasticity modulus and hardness are 84.6 ± 12.6 MPa, 138 ± 7 GPa and 4.44 ± 0.35 GPa, respectively. SEM images show a compact and uniform microstructure; XRD and FTIR determined the phase and the radical preserved after sintering.