Multilayer coatings formed on titanium alloy surfaces by plasma electrolytic oxidation-electrophoretic deposition methods

Tricalcium phosphate was deposited on the surface of anodized titanium alloys (Ti-6Al-7Nb, Ti-13Nb-13Zr and Ti-15Mo) using the electrophoretic technique (EPD). The multilayer coatings were formed by a three-step experiment. The influences of voltage (step I), time (step II) and concentration of TCP in the suspensions (step III) on the ceramic particle deposition was investigated. The appropriate conditions were determined for each titanium alloy surface modification. The total thickness of the anodized titanium alloys increased, the surface roughness decreased and the wettability increased after TCP particle deposition. A TL-XRD investigation showed that the multilayer coatings were mainly amorphous. All the coatings adhered well to the substrate. The surface modifications increased the corrosion resistance in Ringer's solution, particularly for the Ti-15Mo alloy. In addition, the multilayer coatings formed on this titanium alloy exhibited the best cytocompatibility with MG-63 osteoblast-like cells.