Improving Bio Corrosion Resistance of the Single Layer of Nano Hydroxyapatite and Nano YSZ Coating on the Ti6Al4V Alloy Using Electrophoretic Deposition

Abstract

Titanium alloy (Ti6Al4V) has been used extensively applications such as medical implants, but the ion release and the corrosion products can affect their mechanical integrity and biocompatibility. The objective of present work is to improve the bio corrosion resistance the Ti6Al4V Alloy.  One of the solution is used coating the substrate with single layer of nano hydroxyapatite and nano YSZ via electrophoretic deposition technique on this alloy by utilizing ethanol as a solvent under AC. To enhance the quality of the surface alloy and to meet the requirements the activity of the biological orthopedic application, so that a real bond with the surrounding bone tissue can be formed.  A cross section of the coating was characterized by optical microscopes, and SEM. The conditions for precipitation of nano hydroxyapatite (HAP) layer were 60 volts, 6 min, 3g / l, while the conditions for precipitation of nano YSZ were 40 volts, 4 min and 1 g / l at room temperature.  The water contact angles of uncoated samples are changed from high to the low.  The water contact angles for the samples have been changed from hydrophobic to super hydrophilic.  HAp -coated Ti-6Al-4V alloy has a greater resistance to the corrosion in comparison with the uncoated substrate of Ti-6Al-4V in SBF solution. Such enhancement has been supported by shifting to more noble direction of the corrosion potential and a smaller value of the current density of corrosion.