| Issue |
MATEC Web of Conferences
Volume 33, 2015
ESOMAT 2015 – 10th European Symposium on Martensitic Transformations
|
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|---|---|---|
| Article Number | 03011 | |
| Number of page(s) | 6 | |
| Section | NiTi-based alloys | |
| DOI | https://doi.org/10.1051/matecconf/20153303011 | |
| Published online | 07 December 2015 | |
Phase Transformations and Fatigue of NiTi
1 LBMS, ENIB, Technopôle Brest-Iroise, CS73862, 29238 Brest, France
2 Institute of Physics, Academy of Sciences of the Czech Republic, 182 00 Prague, Czech Republic
3 LBMS, ENSTA Bretagne, 29200 Brest, France
a Corresponding author: eduardo.alarcon@ensta-bretagne.org
Tensile fatigue of superelastic medical graded NiTi wires was analysed in stress control regime with special attention paid to the deformation/transformation processes involved. Concave shaped samples were machined from NiTi wires allowing us to confine deformation processes into the centre of the sample. The localization of phase transformations within the centre was confirmed using in-situ infrared imaging. Characteristic stress-displacement responses for amplitudes inducing either R-phase only or both R-phase and martensite were identified for these samples. A limited number of pull-pull fatigue tests in force-control regime were performed. The obtained S-N curve and associated stress-displacement responses allowed for identification of three fatigue regimes differing in the fatigue life-time by orders of magnitude. Particularly, fatigue life-time deteriorating effect of R-phase transformation was identified.
© Owned by the authors, published by EDP Sciences, 2015
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.