Details
| Original language | English |
|---|---|
| Pages (from-to) | 252-254 |
| Number of pages | 3 |
| Journal | Materials letters |
| Volume | 210 |
| Publication status | Published - 8 Sept 2017 |
Abstract
Stress–strain loops illustrating the superelastic behaviour of shape memory alloys (SMAs) were computed based on the theory of ferroelastic phase transitions. The predictions of the theory demonstrate the possibility of drastic changes in the stress–strain dependences due to the expansion of the SMA upon heating. Specifically, the computations were carried out taking into account the characteristics of Co-Ni-Ga alloys, which exhibit a high-temperature superelasticity. It is shown that the expansion of crystal lattice, which can be caused by the appearance of small particles and crystal defects, or change of chemical order in SMA, can induce (i) an extension of the temperature range of superelastic behaviour of SMA to high temperatures; (ii) an increase of the superelastic strain at elevated temperatures; (iii) an increase of the stress needed to reach the superelastic strain plateau and (iv) a widening of the hysteresis of stress-induced martensitic transformation. Theoretical results are in a qualitative agreement with experimental data obtained for Co-Ni-Ga alloys.
Keywords
- Defects, Hysteresis, Phase transformation, Shape memory materials, Strain, Stress
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
- Engineering(all)
- Mechanical Engineering
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In: Materials letters, Vol. 210, 08.09.2017, p. 252-254.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Internal pressure as a key thermodynamic factor to obtain high-temperature superelasticity of shape memory alloys
AU - Gerstein, Gregory
AU - L'vov, Victor A.
AU - Kosogor, Anna
AU - Maier, Hans J.
N1 - Funding information: Financial support by the Deutsche Forschungsgemeinschaft (DFG) under grant MA1175/44-1 is gratefully acknowledged. The authors thank Prof. Chumlyakov for providing the single crystals.
PY - 2017/9/8
Y1 - 2017/9/8
N2 - Stress–strain loops illustrating the superelastic behaviour of shape memory alloys (SMAs) were computed based on the theory of ferroelastic phase transitions. The predictions of the theory demonstrate the possibility of drastic changes in the stress–strain dependences due to the expansion of the SMA upon heating. Specifically, the computations were carried out taking into account the characteristics of Co-Ni-Ga alloys, which exhibit a high-temperature superelasticity. It is shown that the expansion of crystal lattice, which can be caused by the appearance of small particles and crystal defects, or change of chemical order in SMA, can induce (i) an extension of the temperature range of superelastic behaviour of SMA to high temperatures; (ii) an increase of the superelastic strain at elevated temperatures; (iii) an increase of the stress needed to reach the superelastic strain plateau and (iv) a widening of the hysteresis of stress-induced martensitic transformation. Theoretical results are in a qualitative agreement with experimental data obtained for Co-Ni-Ga alloys.
AB - Stress–strain loops illustrating the superelastic behaviour of shape memory alloys (SMAs) were computed based on the theory of ferroelastic phase transitions. The predictions of the theory demonstrate the possibility of drastic changes in the stress–strain dependences due to the expansion of the SMA upon heating. Specifically, the computations were carried out taking into account the characteristics of Co-Ni-Ga alloys, which exhibit a high-temperature superelasticity. It is shown that the expansion of crystal lattice, which can be caused by the appearance of small particles and crystal defects, or change of chemical order in SMA, can induce (i) an extension of the temperature range of superelastic behaviour of SMA to high temperatures; (ii) an increase of the superelastic strain at elevated temperatures; (iii) an increase of the stress needed to reach the superelastic strain plateau and (iv) a widening of the hysteresis of stress-induced martensitic transformation. Theoretical results are in a qualitative agreement with experimental data obtained for Co-Ni-Ga alloys.
KW - Defects
KW - Hysteresis
KW - Phase transformation
KW - Shape memory materials
KW - Strain
KW - Stress
UR - http://www.scopus.com/inward/record.url?scp=85029371920&partnerID=8YFLogxK
U2 - 10.1016/j.matlet.2017.09.034
DO - 10.1016/j.matlet.2017.09.034
M3 - Article
AN - SCOPUS:85029371920
VL - 210
SP - 252
EP - 254
JO - Materials letters
JF - Materials letters
SN - 0167-577X
ER -