Synthesis, Sintering and Characteristics of Hydroxyapatite Nanopowder

The chemical interaction between calcium hydroxide and phosphoric acid was chosen for synthesis of the HAP nanopowder. Various methods for manufacturing dense HAP materials from obtained powders were used and compare

Synthesis, Sintering and Characteristics of Hydroxyapatite Nanopowder

Synthesized HAP nanopowder shows the agglomerate which consist of nanosized rod-shaped particles in size of 50–100 nm. The powder obtained by spray-drying consisted from quasi spherical granules with average diameter of 20-40 μm.The specific surface area of such powder was in the range of 60-70 m2/g. The XRD pattern of the powder showed low crystallinity.The specific surface area of such powder was in the range of 60-70 m2/g. The XRD pattern of the powder showed low crystallinity.All used methods allows to manufacture the dense HAP materials but more promising method seems to be the MW sintering because only this method allows to obtain dense HAP material at relatively low temperature and in short time – at 900 oC in 15 minutes (Table 1). This provides the saving of nanosize microstructure of the material and therefore the high values of fracture toughness up to 1.5 MPa·m1/2, microhardness up to 5 GPa