Interstitial impurities in NiTi-based shape memory alloys
Investigator: prof. RNDr. Antonín Dlouhý, CSc.
Number of Project: 15-16336S
Agency: Czech Science Foundation
Duration: 01. 01. 2015 - 31. 12. 2017
The project focuses on interactions between NiTi shape memory alloys and environments that assist heat treatments and in-vivo applications. We address two opened questions related to microstructure and B2-R-B19’ martensitic transformations: (i) why hydrogen atoms stabilize B2 and R lattices and suppress respective transformations to B19’ martensite and (ii) how oxygen and/or hydrogen atoms influence Ni4Ti3 precipitation and subsequent transformations in Ni-rich alloy variants. These issues are closely related to the embrittlement of NiTi superelastic stents during long-term in-vivo exposures. Thus the attention is also given to changes in structure and properties of NiTi alloys exposed to in-vivo environmental conditions. We expect the following results: (i) a new insight into the mechanism by means of which the interstitial impurities influence microstructure and the path of martensitic transformation, (ii) a microstructurally based scenario accounting for embrittlement of superelastic NiTi components subjected to in-vivo environments.
Ševčíková J., Bártková D., Goldbergová M., Kuběnová M., Čermák J., Frenzel J., Weiser A., Dlouhý A.
On the Ni-Ion release rate from surfaces of binary NiTi shape memory alloys
Applied Surface Science 427 (2018) p. 434-443
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central european institute of technology


Last update
19. 03. 2018