Bioactive element coatings on nano-mesh formed Ti-6Al-4V alloy surface using plasma electrolytic oxidation

Abstract

Bioactive element coatings on nano-mesh formed Ti-6Al-4V alloy surface using plasma electrolytic oxidation were studied. Ti-6Al-4V alloy was used for nano-mesh formation, which was carried out in 1 M H3PO4 + 0.8 wt% NaF at 30 V for 1 h. For micro-pore formation, plasma electrolytic oxidation (PEO) treatment was performed in a solution containing bioactive ions at 280 V for 3 min. After that, surface and biological characteristics were investigated using FE-SEM, EDS, AFM, Scratch test, XRD, wettability test, and MC3T3–1 cell culture test.The nanotubes and nano-mesh were well formed in the α-phase compared to β-phase. The many micro-sized pores on PEO(5ion) samples were formed with circular and irregularly shaped pores and the circular precipitate with oxide thickness of 2.0– 3.0 μm. PEO(5ion) and PEO(Ca + P) samples consisted of anatase and HA phases, and the surface roughness of the PEO samples was higher than those of nanotube and nano-mesh formed surface, whereas, the contact angle of the PEO samples was lower than those of nanotube and nano-mesh formed surface. The adhesive strength of the PEO(5ion) films showed higher compared to PEO(Ca + P) sample. The number of cells on the modified surface and oxide layers increased with the surface roughness. The cell growth and proliferation on the PEO(5ion) films were higher than those of polished surface, the adhesion of cells is greatly improved on the nano-mesh surface.