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

Maciej Sowa; Katarzyna Greń; Andrey I Kukharenko; Danila M Korotin; Joanna Michalska; Lilianna Szyk-Warszyńska; Michał Mosiałek; Jerzy Zak; Elżbieta Pamuła; Ernst Z Kurmaev; Seif O Cholakh; Wojciech Simka

doi:10.1016/j.msec.2014.05.065

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

Mater Sci Eng C Mater Biol Appl. 2014 Sep:42:529-37. doi: 10.1016/j.msec.2014.05.065. Epub 2014 Jun 6.

Affiliations

¹ Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice, Poland.
² Institute of Metal Physics, Russian Academy of Sciences-Ural Division, S. Kovalevskoi Street 18, 620990 Yekaterinburg, Russia; Ural Federal University, Mira Street 19, 620002 Yekaterinburg, Mira str. 19, Russia.
³ Institute of Metal Physics, Russian Academy of Sciences-Ural Division, S. Kovalevskoi Street 18, 620990 Yekaterinburg, Russia.
⁴ Faculty of Materials Engineering and Metallurgy, Silesian University of Technology, Krasińskiego Street 8, 40-019 Katowice, Poland.
⁵ Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek Street 8, 30-239 Kraków, Poland.
⁶ AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza Avenue 30, 30-059 Kraków, Poland.
⁷ Ural Federal University, Mira Street 19, 620002 Yekaterinburg, Mira str. 19, Russia.
⁸ Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice, Poland. Electronic address: wojciech.simka@polsl.pl.

PMID: 25063150
DOI: 10.1016/j.msec.2014.05.065

Abstract

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. Thusly prepared niobium samples were additionally investigated in terms of their corrosion resistance in Ringer's solution. The electropolished niobium surface was determined to be smooth and lustrous. The anodisation led to the growth of barrier-like oxide layers, which were enriched in phosphorus species.

Keywords: Anodic oxidation; Corrosion resistance; Electropolishing; Niobium; Phosphoric acid; X-ray photoelectron spectroscopy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Corrosion*
Electrochemical Techniques*
Niobium / chemistry*
Oxidation-Reduction*
Phosphoric Acids
Photoelectron Spectroscopy
Surface Properties

Substances

Phosphoric Acids
Niobium
phosphoric acid