Comparative Study of Hydroxyapatite Synthesized by High Energy Ball Milling in Wet and Dry Conditions

Mechanochemical method was used to obtain nano-size hydroxyapatite/HA powder, both in wet and dry conditions, by using CaCO3 and (NH4)H2(PO4) as starting materials. Nano-particles of HA were obtained by high energy ball milling in wet conditions having rotation speed of 600 rpm/10 h by taking ethanol as grinding liquid and zirconia balls as grinding media. From EDS analysis, an additional peak of aluminium/Al was observed in wet milled HA powders, whereas no such additional peak was observed in dry milled HA powders. Dry milling was carried out at 300 rpm with 5 h milling time. Average particle size of HA from FESEM analysis was found to be in 27–80 nm range dry milled powders. XRD study shows evolution of the pure HA phase. Optimized calcination and sintering temperature of the HA system were at 800 °C and 1000 °C, respectively, synthesized using microwave-assisted high energy ball milling technique.