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
| Investigator | prof. RNDr. Antonín Dlouhý, CSc. |
| Number of Project | 15-16336S |
| Agency | Grantová agentura České republiky |
| Duration | 2014-12-31 - 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. |
