2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 6: Rare Earths & Ionic Liquids
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 432 pages |
| ISBN: | 978-1-987820-08-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Corrosion resistance of Ti-6Al-4V in molten chloro-fluoride
Ana-Maria Julieta Popescu1; Elena Ionela Neacsu2; Marcelle Gaune-Escard3; Kazimir Yanushkevich4; Cristina Donath1; Virgil Constantin2;1ILIE MURGULESCU INSTITUTE OF PHYSICAL CHEMISTRY, LABORATORY OF MOLTEN SALTS, Bucharest, Romania; 2ILIE MURGULESCU INSTITUTE OF PHYSICAL CHEMISTRY, Bucharest, Romania; 3ECOLE POLYTECHNIQUE, CNRS UMR 6595, Marseille, France; 4SCIENTIFIC-PRACTICAL MATERIALS RESEARCH CENTRE NAS, Minsk, Belarus;
Type of Paper: Regular
Id Paper: 114
Topic: 11
Abstract:
The titanium alloys are potential materials for high temperature applications in turbine components due to their very high temperature strength and lightweight properties. The Ti-6Al-4V alloy has been increasingly used in biomedical, aerospace and chemical industries due to their high strength to weight ratio and high corrosion resistance. However, hot corrosion is a life-limiting factor when Ti alloys are exposed to different chemical environments at high temperature. In this study, hot corrosion behavior of Ti-6Al-4V alloy in NaCl-LiF-KCl was investigated at 7400C. The corrosion parameters were calculated by polarization measurements and compared to these of pure Ti. The morphology of the Ti-Al-V was observed by micrograph, X-ray diffraction (XRD), metallographic micrography and AFM. The scale formed on the samples upon hot corrosion was characterized by using XRD, micrographs and AFM analysis to understand the degradation mechanism of the titanium alloy. The information on the exposed surface in the electrolyte and the relative atomic concentration was obtained by XPS analysis method. The XPS analysis shows that TiO2 was the main phase with small amount of V2O5, Al2O3 and TiOCl. The XPS analysis of the electrolyte showed the presence of vanadium in a very low concentration. The binding energies for the formed compounds before and after corrosion were calculated. Even if the corrosion rate of Ti-Al-V is much lower than that of Ti, it is observed that the corrosion rate of titanium alloy is relatively high in molten salt. The degradation occurs due to the chemical reaction of titanium with chloride ions and of aluminium with fluoride ions.