Phase Composition of Coatings Formed on Titanium in Borate Electrolyte by Microarch Oxidation

The effect of oxidation conditions, temperature and concentration of the electrolyte, and its transformation from the true to colloidal solution on the phase composition and electrical resistance of coatings was studied.     

Silicate coatings on titanium, modified with transition metal oxides and their activity in CO oxidation

CuO+M _x O _y /TiO₂+SiO₂/Ti composites (M = Mn, Fe, Co, Ni) were produced by plasma-electrolytic oxidation and impregnation, followed by annealing. The elemental and phase composition of these composites were examined and their activity series in CO oxidation was determined.     

The organization of the surface of multicomponent plasma-electrolytic anode layers on aluminum

The elemental composition of characteristic formations on the surface of anodic films containing transition metal compounds (Ni, Cu, Co, Mn, and W) and formed on an aluminum alloy in aqueous electrolytes under the conditions of the action of electric spark and arc discharges (plasma-electrolytic or plasmaelectrochemical oxidation) was studied. The main formations on the surface were fritted structures, pores, caverns covered by “lids” on top, and disperse particles (microgranules). Electrolyte transition metals largely concentrated in caverns, pores, and microgranules. The composition of microgranules was different from that of caverns, pores, and fritted structures. The main elements that formed microgranules were nickel and carbon. Cobalt and manganese were differently built into surface formations. Cobalt replaced nickel in micro-granules, and manganese replaced aluminum in fritted surface structures.     

Calcium-containing biocompatible oxide-phosphate coatings on titanium

Formation of biocompatible coatings containing TiO₂ along with various calcium phosphates, including hydroxyapatite, on a titanium surface was studied by plasma electrolytic oxidation.     

Structures and magnetic properties of iron- and cobalt-containing oxide coatings on an aluminum alloy formed in electrolytes via plasma electrolytic oxidation

The effect of the nature of the supporting electrolyte in the composition of electrolytic suspensions containing dispersed particles of Fe(III) and Co(II) hydroxides, and of anodic and bipolar anodic-cathodic polarization on features of the formation, composition, and magnetic characteristics of oxide coatings is studied. In all cases, iron and cobalt are incorporated into the coatings and are concentrated predominantly in pores. The pores of the coatings include particles consisting of the reduced metals, presumably surrounded by oxide or hydroxide shells. The electrolyte composition affects the concentration and ratio of the metals in the particles. A correlation is observed between the ferro- or ferrimagnetism of the coatings and the content and ratio of cobalt and iron in the pores.     

Preparation,properties, and catalytic activity of platinum-modified plasma electrolytic oxide structures on aluminum

Catalytically active Pt-containing oxide composites on aluminum have been prepared by plasma electrolytic oxidation (PEO) and by additional modification of the resulting coating by impregnation with an aqueous solution of chloroplatinic acid followed by calcination. The oxide film/metal composites have been characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy. The modified films contain the γ-Al₂O₃ and Pt crystalline phases. Platinum in the surface and subsurface layers is in the Pt⁰ state. There are platinum-rich areas on the surface of the PEO films. A higher catalytic activity in CO oxidation into CO₂ is shown by the samples whose oxide film contains nickel and copper along with platinum.     

Plasma electrolytic synthesis and characterization of pH-sensitive TiO2-ZrO2-ZrTiO4-CeOx films on titanium

Journal of Solid State Electrochemistry - The Ti/TiO2 + ZrO2, Ti/TiO2 + CeOx, and Ti/TiO2 + CeOx + ZrO2 composites, including Y-doped ones, have been...     

Deposition,composition, and activity in CO oxidation of anodic layers with platinum on aluminum and titanium

Pt + TiO₂/Ti(Al) and Pt + CeO₂ + ZrO₂ + TiO₂/Ti composites were formed by plasma electrolytic oxidation and their surface composition and catalytic activity in CO oxidation to CO₂ were studied.     

Ta-containing oxide coatings on titanium for biomedical application

Bioinert, biocompatible, chemical-resistant oxide coatings containing Ta₂O₅, which are promising to be applied to titanium implants, were produced on titanium by plasma electrolytic oxidation in an aqueous electrolyte. An effect of formation conditions on the elemental and phase composition, thickness, and roughness of the coatings was researched. It was found that an addition of polyethylene glycol to electrolyte without affecting the elemental composition and the thickness causes a change in the porosity and an increase in the roughness of the formed oxide layer. Changing the surface arrangement may allow affecting an adhesion of biotissues to titanium implants with coatings and accumulating drugs by the coatings.