SEM, EDS and XPS analysis of the coatings obtained on titanium after plasma electrolytic oxidation in electrolytes containing copper nitrate

摘要

In the paper, the Scanning Electron Microscopy (SEM) with Energy Dispersive X-raySpectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS) results of the surface layer formedon pure titanium after plasma electrolytic oxidation (micro arc oxidation) at the voltage of 450 Vare shown. As an electrolyte, the mixture of copper nitrate Cu(NO3)2 (10–600 g/L) in concentratedphosphoric acid H3PO4 (98 g/mol) was used. The thickness of the obtained porous surface layerequals about 10 m, and it consists mainly of titanium phosphates and oxygen with embeddedcopper ions as a bactericidal agent. The maximum percent of copper in the PEO surface layer wasequal to 12.2 0.7 wt % (7.6 0.5 at %), which is the best result that the authors obtained. The topsurface layer of all obtained plasma electrolytic oxidation (PEO) coatings consisted most likely mainlyof Ti3(PO4)4 nH3PO4 and Cu3(PO4)2 nH3PO4 with a small addition of CuP2, CuO and Cu2O.