Sol-gel preparation and properties of Ag-TiO₂ films on surface roughened Ti-6Al-4V alloy

Ag-TiO₂ films (Ag/Ti=3·3, 9·1 at-%) were sol-gel coated on Ti-6Al-4V alloy that had been surface roughened by the NaOH-HCl treatment for antibacterial applications. Scanning electron microscopy observation showed that pore size of the surface layer of NaOH-HCl treated Ti- 6Al-4V alloy increased with the NaOH concentration. Ag-TiO₂ films on the surface roughened substrate were adherent and crack-free. X-ray photoelectron spectroscopy and Auger electron spectroscopy analyses indicated that Ag existed in metallic state, and the films completely covered the roughened substrate. X-ray diffraction peaks of the substrate and anatase TiO₂ were detected. The Ag-TiO₂ films on the roughened substrate exhibited good adhesion quality and high cohesion strength in the indentation test. The potentiodynamic polarisation test showed that the TiO₂ and Ag-TiO₂ films improved corrosion resistance of the substrate.