In this paper results of the surface modification of the Ti-15Mo, Ti-13Nb-13Zr, Ti-6Al-7Nb alloys by plasma electrolytic oxidation (PEO) coupled by electrophoretic deposition (EPD) technique were presented. On the porous oxide layers hydroxyapatite (HA) particles were deposited, filled cracks and pores of the coatings. The surfaces of the titanium alloys were modified to enhance their corrosion resistance and bioactivity in biological environment. The influence of voltage, time of the EPD process, and bath composition on hydroxyapatite particles deposition on the porous samples were studied. Microstructure, cross-section, phase composition, surface roughness and wettability of the multilayer coatings were determined. Electrochemical investigations shown, that the titanium alloys surfaces modification improved corrosion resistance of the substrates in Ringer solution. Scratch testing shown that the coatings exhibit good adhesion to the substrate. The coatings formed on the titanium alloys surface were bioactive. After simulated body fluid (SBF) immersion, on all of the samples the apatite crystallized and covered the coatings.

Present work describes investigations of a two-step process consisting of galvanostatic anodising in a 1 M H 2 SO 4 solution at 100 mA cm −2 up to the limiting voltages of 20, 60, 80, 100 and 120 V, directly after which potentiostatic regime was employed and the current was allowed to drop. The total treatment time (5 min) was held constant for all samples. The treatment was carried out to improve the corrosion resistance of zirconium in physiological conditions, which was determined by electrochemical evaluation in Ringer's solution. XPS studies revealed that after anodising sulphur was incorporated into the oxide film in the form of sulphated zirconia. The maximum content of sulphate in the oxide layer was observed after anodising at 80 V. Anodising at higher voltages resulted in formation of coatings with decreasing amount of sulphur. It was found that there is a strong correlation between the sulphur content in the oxide layers and the measured corrosion current density. On the other hand, the pitting corrosion resistance seemed to be unaffected by the presence of S and it was improving with the increasing limiting voltage of the treatment.