Influence of electropolishing and anodic oxidation on morphology, chemical composition and corrosion resistance of niobium.

The work presents results of the studies performed on electropolishing of pure niobium in a bath that contained: sulphuric acid, hydrofluoric acid, ethylene glycol and acetanilide. After the electropolishing, the specimens were subjected to anodic passivation in a 1moldm(-3) phosphoric acid solution at various voltages. The surface morphology, thickness, roughness and chemical composition of the resulting oxide layers were analysed.

Surface characterisation of Ti-15Mo alloy modified by a PEO process in various suspensions.

This paper reports on the surface modification of a Ti-15Mo alloy by plasma electrolytic oxidation (PEO). This process was carried out in solutions of 0.1M Ca(H2PO2)2 with various concentrations of tricalcium phosphate (Ca3(PO4)2), wollastonite (CaSiO3), or silica (SiO2) using voltages of up to 350V.