Sol–gel derived alumina–hydroxyapatite–tricalcium phosphate porous composite powders

In this study, alumina–hydroxyapatite–tricalcium phosphate (α-Al2O3–HA–TCP) porous composite powders were produced and characterized. At first, boehmite sol (AlOOH) was obtained via sol–gel process by using aluminium isopropoxide (Al(OC3H7)3) as the starting material. Bovine hydroxyapatite (BHA) powders derived from deproteinized bovine bones were added as 10, 20, 30 and 50% weight of the starting material to each boehmite sol. Also Na-alginate was added to the boehmite sol as the dispersive agent. Subsequently, gelation for 3h at 110°C was applied to each sol mixture. Finally, gelated samples were heat treated for 2h at 500, 800, 1000 and 1300°C. DTA–TGA, XRD, FTIR and SEM-EDS analyses were used to characterize the obtained composite powders composed of α-Al2O3–HA–TCP phases. In order to investigate porosity properties, powders were pressed with hydraulic manual press and formed into pellets. Later these pellets were sintered for 2h at 1300°C. Apparent porosity and bulk density tests were applied to the pellets. The evaluation of these tests results indicate that a novel α-Al2O3–HA–TCP composite material with ∼38–44% apparent porosity has been produced.