Surface chemistry and topographical changes of an electropolished NiTi shape memory alloy
Sprache des Titels:
Englisch
Original Kurzfassung:
Electropolishing and its mechanism for NiTi shape memory alloy in methanolic sulfuric acid have been investigated recently. In the current study, X-ray photoelectron spectroscopy was carried out to characterize the chemical nature of the electropolished surface. The electropolished surface is covered by a thin layer of TiO2. For an electropolished specimen, the Ni:Ti ratio at surface (~1 nm) was 0.31, whereas for a mechanically polished specimen the ratio was 0.70. The second aspect of this work is the attempt to characterize the salt film formed during electropolishing. The characterization of salt-film showed sulfide and sulfate compounds of Ni and/or Ti. The crystallographic and topographical changes caused due to thermally induced phase transformation on an electropolished NiTi was followed by in situ XRD and AFM. AFM studies revealed significant changes in the surface features due to phase transformation. The surface roughness value increased by a factor of 2.
Sprache der Kurzfassung:
Englisch
Journal:
Physica Status Solidi A: Applications and Materials Science
Volume:
207
Seitenreferenz:
807-811
Erscheinungsjahr:
2010
ISSN:
1862-6300
Anzahl der Seiten:
5
Notiz zur Publikation:
1)Max-Planck-Institut für Eisenforschung, Max-Planck-Str.1, 40237 Düsseldorf, Germany
2)Institut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr.150, 44801 Bochum, Germany
3)Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University, Linz, Austria
- 1Lakshman Neelakantan, 1Markus Valtiner, 2Gunther Eggeler,1,3Achim Walter Hassel
Forschungs-