In Situ Formation of Hydroxyapatite During Powder Metallurgy Preparation of Porous Ti/HA Nano Composite: A Candidate for Dental Implants

Abstract

Porous Ti/HA nano-composite was prepared for implant fixtures and in situ formation of Hydroxyapatite. At first, Ca(OH) 2 nanoparticles were synthesized by precipitation. Raw materials included Ca(NO 3) 2 .4H 2 O, NaOH, a mixture of deionized water and ethanol. Synthesized Ca(OH) 2 nano powder was mixed with (NH 4) 2 HPO 4 and the mixture was calcined at 700 ºC for 30 min. After calcination, Ca 2 P 2 O 7 and CaPO 3 (OH).2H 2 O were synthesized with imperfect hexagonal morphology. The resulting powder was mixed with pure titanium powder and pressed under 300, 500 and 700 MPa. The samples were sintered at 1000 ºC for an hour under pure argon. Final composition was Ti/HA with hexagonal morphology. XRD and SEM showed the in situ formation of nano hydroxyapatite besides titanium phases during the sintering procedure. The density and open porosity of the 700 MPa pressed-samples were 3.07 g/cm 3 and 28.2%, respectively. In general, porous Ti/HA nanocomposite with suitable porosity could be successfully synthesized by co-precipitation procedure.