Effect of Voltage and Time on the Electrophoretic Deposition of Hydroxyapatite and Hydroxyapatite-Tantalum Pentoxide Coatings on NiTi

In the present study, natural hydroxyapatite (nHA) and nHA-20%wt Ta2O5 (nHA-Ta2O5)nanocomposite coatings were deposited via electrophoretic deposition (EPD) on NiTi alloysfrom n-butanol as medium and triethanolamine as dispersant. The phase composition andparticles size of nHA powder were characterized using XRD and TEM respectively. In order tooptimizing the process voltage and time, EPD was conducted at constant voltage, namely at50, 60 and 70 for various durations of 30, 60 and 120 s. The effects of EPD voltages andtimes on the microstructure and thickness of green coatings were examined by SEM. Theuniform, continuous and crack-free coatings were obtained from stable nHA and nHA-Ta2O5suspensions at 60 and 60 with respectively 30 and 25 μm thicknesses. The EPD kinetic aswell as current density was studied during deposition at 50, 60 and 70 V. It was observed thatat all of the same conditions, nHA-Ta2O5 composite coatings have higher in situ deposit weightsthan nHA coatings.

Effect of Voltage and Time on the Electrophoretic Deposition of Hydroxyapatite and Hydroxyapatite-Tantalum Pentoxide Coatings on NiTi Keywords:

NiTi alloy , Natural hydroxyapatite nanoparticles , Electrophoretic Deposition , Hydroxyapatite-tantalum pentoxide coatings