Details
| Original language | English |
|---|---|
| Pages (from-to) | 37-49 |
| Number of pages | 13 |
| Journal | Shape Memory and Superelasticity |
| Volume | 2 |
| Issue number | 1 |
| Publication status | Published - 30 Dec 2015 |
Abstract
Conventional shape memory alloys (SMAs), such as binary Ni–Ti, are typically limited to service temperatures below 100 °C. Recent studies on Co–Ni–Ga high-temperature SMAs revealed the potential that these alloys can be used up to temperatures of about 400 °C. Analysis of the cyclic functional properties showed that degradation in these alloys is mainly triggered by intensive dislocation motion. However, data on the cyclic stress–strain response and the mechanisms leading to functional degradation of Co–Ni–Ga above 300 °C were missing in open literature. Current results reveal that above 300 °C diffusion-controlled mechanisms, e.g., precipitation of secondary phases and changes in the chemical degree of order, seem to dictate cyclic instability. Detailed neutron and transmission electron microscopy analyses following superelastic cycling in a temperature range of 200–400 °C were employed to characterize the changes in degradation behavior above 300 °C.
Keywords
- Functional degradation, Martensite stabilization, Martensitic phase transformation, Shape memory alloy (SMA), Superelasticity
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Engineering(all)
- Mechanics of Materials
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Shape Memory and Superelasticity, Vol. 2, No. 1, 30.12.2015, p. 37-49.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Cyclic Degradation of Co49Ni21Ga30 High-Temperature Shape Memory Alloy
T2 - On the Roles of Dislocation Activity and Chemical Order
AU - Krooß, P.
AU - Kadletz, P. M.
AU - Somsen, C.
AU - Gutmann, M. J.
AU - Chumlyakov, Y. I.
AU - Schmahl, W. W.
AU - Maier, H. J.
AU - Niendorf, T.
N1 - Funding information: Financial supports by the Deutsche Forschungsgemeinschaft (DFG) within the Research Unit Program “Hochtemperatur-Formgedächtnislegierungen” (Contract Nos. NI1327/3-2; MA1175/34-2; SCHM 930/13-2 and SO505/2-2) and by the Tomsk State University Academic D.I. Mendeleev Fund Program are gratefully acknowledged.
PY - 2015/12/30
Y1 - 2015/12/30
N2 - Conventional shape memory alloys (SMAs), such as binary Ni–Ti, are typically limited to service temperatures below 100 °C. Recent studies on Co–Ni–Ga high-temperature SMAs revealed the potential that these alloys can be used up to temperatures of about 400 °C. Analysis of the cyclic functional properties showed that degradation in these alloys is mainly triggered by intensive dislocation motion. However, data on the cyclic stress–strain response and the mechanisms leading to functional degradation of Co–Ni–Ga above 300 °C were missing in open literature. Current results reveal that above 300 °C diffusion-controlled mechanisms, e.g., precipitation of secondary phases and changes in the chemical degree of order, seem to dictate cyclic instability. Detailed neutron and transmission electron microscopy analyses following superelastic cycling in a temperature range of 200–400 °C were employed to characterize the changes in degradation behavior above 300 °C.
AB - Conventional shape memory alloys (SMAs), such as binary Ni–Ti, are typically limited to service temperatures below 100 °C. Recent studies on Co–Ni–Ga high-temperature SMAs revealed the potential that these alloys can be used up to temperatures of about 400 °C. Analysis of the cyclic functional properties showed that degradation in these alloys is mainly triggered by intensive dislocation motion. However, data on the cyclic stress–strain response and the mechanisms leading to functional degradation of Co–Ni–Ga above 300 °C were missing in open literature. Current results reveal that above 300 °C diffusion-controlled mechanisms, e.g., precipitation of secondary phases and changes in the chemical degree of order, seem to dictate cyclic instability. Detailed neutron and transmission electron microscopy analyses following superelastic cycling in a temperature range of 200–400 °C were employed to characterize the changes in degradation behavior above 300 °C.
KW - Functional degradation
KW - Martensite stabilization
KW - Martensitic phase transformation
KW - Shape memory alloy (SMA)
KW - Superelasticity
UR - http://www.scopus.com/inward/record.url?scp=84985012315&partnerID=8YFLogxK
U2 - 10.1007/s40830-015-0049-5
DO - 10.1007/s40830-015-0049-5
M3 - Article
AN - SCOPUS:84985012315
VL - 2
SP - 37
EP - 49
JO - Shape Memory and Superelasticity
JF - Shape Memory and Superelasticity
SN - 2199-384X
IS - 1
ER -