Synthesis Of Nano-Size Hydroxyapatite (Hap) Powders By Mechanical Alloying

Nano hydroxyapatite (Ca 10(PO 4) 6(OH) 2, HAp) powders were synthesized by solid-state reaction of Ca(OH) 2 and P 2O 5 mixtures in a high-energy SPEX 8000 shaker mill, using hardened steel vial and balls. The phase analysis was carried out using X-ray powder diffraction technique. Transformation of Ca(OH) 2 and P 2O 5 mixture to HAp phase was first observed after 1 h of milling. The powder milled for 3 h showed prominently the presence of HAp phase. TEM analysis revealed that as-synthesized HAp powder was in the range of 20-60 nm. Measured quantities of synthesized nano-powders were pressed uniaxially in a steel mold to prepare dense ceramic structures for densification studies. These green structures were subjected to sintering studies at 1300°C for 6 h when the highest sintered density of 3.17 g/cc was achieved