Corrosion of NiTi wires with cracked oxide layer

0432510 - FZÚ 2015 RIV US eng J - Journal Article
Racek, Jan - Šittner, Petr - Heller, Luděk - Pilch, Jan - Petrenec, M. - Sedlák, Petr
Corrosion of NiTi wires with cracked oxide layer.
Journal of Materials Engineering and Performance. Roč. 23, č. 7 (2014), s. 2659-2668. ISSN 1059-9495. E-ISSN 1544-1024.
[International Conference on Shape Memory and Superelastic Technologies (SMST 2013). Praha, 21.05.2013-24.05.2013]
R&D Projects: GA ČR GPP108/12/P111; GA ČR GAP107/12/0800; GA MŠMT(CZ) 7E11058
EU Projects: European Commission(XE) 262806 - SmartNets
Institutional support: RVO:68378271 ; RVO:61388998
Keywords : bending * electrochemical corrosion tests * martensitic transformation * shape memory alloy * superelastic NiTi wires
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 0.998, year: 2014

Corrosion behavior of superelastic NiTi shape memory alloy wires with cracked TiO2 surface oxide layers was investigated by electrochemical corrosion tests (Electrochemical Impedance Spectroscopy, Open Circuit Potential, and Potentiodynamic Polarization) on wires bent into U-shapes of various bending radii. Cracks within the oxide on the surface of the bent wires were observed by FIB–SEM and TEM methods. The density and width of the surface oxide cracks dramatically increase with decreasing bending radius. The results of electrochemical experiments consistently show that corrosion properties of NiTi wires with cracked oxide layers (static load keeps the cracks opened) are inferior compared to the corrosion properties of the straight NiTi wires covered by virgin uncracked oxides.
Permanent Link: http://hdl.handle.net/11104/0236848