Forming hydroxyapatite-containing Titaniacoatings on Ti6Al4V biomedical alloy via plasma electrolytic oxidation and evaluation of its corrosion behavior in simulated body fluid

Titanium and its alloys, especially Ti6Al4V, are widely used inside the human body, as artificial joints, bone staples and screws, dental implants, etc, due to their suitable corrosion resistance, high strength to weight ratio and biocompatibility. Hydroxyapatite, which is a bioactive ceramic can further improve the corrosion resistance and osseointegration of titanium. In this study, hydroxyapatite and titania, in the form of rutile, were produced on Ti6Al4V alloy by means of plasma electrolytic oxidation (PEO) process in constant voltage mode. Different electrical parameters such as frequency, duty cycle and process time were examined. Morphology, cross section and chemical composition of the coatings were evaluated by scanning electron microscope (SEM) and X-ray diffraction (XRD). Electrochemical corrosion behavior of the samples was determined by potentiodynamic polarization test in phosphate buffered saline (PBS) solution at 37 ˚C. The results showed that the sample coated under the frequency of 100 Hz, duty cycle of 40% and process time of 5 minutes had the best corrosion resistance.

کلیدواژه ها:

Ti6Al4V ، Plasma electrolytic oxidation ، Hydroxyapatite ، Titania ، Electrical parameters