Surface Characteristics of Nano-Structured Silicon/Hydroxyapatite Deposition onto the Ti-Nb-Zr Alloy

The Ti-Nb-Zr alloy was manufactured with 35 wt% of Nb and 10 wt% of Zr by arc melting furnace to be a beta phase. Electrochemical deposition of Si substituted Ca/P was performed by pulsing the potential with a method of cyclic voltammetry, and changed cyclic time between 10, 30, 70, and 150. The electrolyte was prepared by dissolving the reagent-grade chemicals: Ca(NO3)2, NH4H2PO4, and Na2SiO3 x 9H20 to be 1.67 of Ca/P ratio and silicon contents were controlled to be 1 wt%. The surface characteristics were observed by field-emission scanning electron microscopy, X-ray diffractometer, and electrochemical corrosion as a potentiodynamic test. The Si substituted hydroxyapatite layer was successfully formed on the Ti-35Nb-10Zr alloy substrate by electrochemical deposition. A surface morphologies showed needle like shape at 10 cycles, then changed to be a circular with increment of cycles. The Ca/P ratio was the range between 1.5 and 2.0, the crystalline of hydroxyapatite could be confirmed. The corrosion behavior of Si-HA deposition was related with surface shape and thickness by increment, of cyclic times. Higher cyclic times of deposition had higher corrosion potential and current density than that of lower cyclic surface.