Institute of Physics of Materials AS CR, v. v. i. > Projects > Interstitial impurities in NiTi-based shape memory alloys

Interstitial impurities in NiTi-based shape memory alloys

Investigatorprof. RNDr. Antonín Dlouhý, CSc.
Number of Project15-16336S
AgencyGrantová agentura České republiky
Duration2014-12-31 - 2017-12-30

Anotace
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.


2020

Veverková J., Bártková D., Weiser A., Dlouhý A., Babula P., Stepka P., Goldbergová M.: Effect of Ni ion release on the cells in contact with NiTi alloys. Environ Sci Pollut R 27 (2020) 7934-7942



2019

Weiser A., Buršíková V., Jarý M., Dymáček P., Dugáček J., Frenzel J., Čermák J., Dlouhý A.: Strength of hydrogen-free and hydrogen-doped Ni50Ti50 shape memory platelets . Scr. Mater. 162 (2019) 151-155



2018

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. Appl. Surf. Sci. 427 (2018) 434-443

Válková L., Ševčíková J., Pávková Goldbergová M., Weiser A., Dlouhý A.: Osteoarthritic process modifies expression response to NiTi alloy presence. J. Mater. Sci. Mater. M. 29 (2018) 146