Details
| Original language | English |
|---|---|
| Pages (from-to) | 538-550 |
| Number of pages | 13 |
| Journal | Mechanics of materials |
| Volume | 38 |
| Issue number | 5-6 |
| Publication status | Published - May 2006 |
| Externally published | Yes |
Abstract
We present an extensive set of experimental results on deformation behavior under external stress and thermal hysteresis behavior of FeNiCoTi shape memory alloys. The experiments spanned from temperatures where the martensite variant motion is responsible for shape changes to cases where stress-induced transformation from austenite to martensite occurred. A temperature hysteresis of the order of 130°C and recoverable strains approaching 3.5% were observed in these materials. These recoverable strain magnitudes far exceed previously reported values on FeNiCoTi alloys. We identify the role of increased slip resistance via aging as partially responsible for increased reversibility and increase in transformation strains. The relaxation of the stored energy due to presence of dislocations at austenite-martensite interfaces was identified with transmission electron microscopy studies, and this is the primary mechanism for large thermal hysteresis as well as the limiting factor in reversibility of the transformation. The changes in transformation temperatures and the hysteresis behavior in the presence of coherent precipitates were rationalized based on a thermodynamics based mechanics model.
Keywords
- Aging, Austenite, Ferromagnetic shape memory alloy, Hysteresis, Iron-based shape memory alloy, Martensite, Modeling, Phase transformation
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Instrumentation
- Engineering(all)
- Mechanics of Materials
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In: Mechanics of materials, Vol. 38, No. 5-6, 05.2006, p. 538-550.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Hysteresis and deformation mechanisms of transforming FeNiCoTi
AU - Sehitoglu, Huseyin
AU - Efstathiou, C.
AU - Maier, H. J.
AU - Chumlyakov, Y.
N1 - Funding Information: The work is supported by the Air Force Office of Scientific Research, Arlington, Virginia, Directorate of Aerospace and Materials Sciences. Prof. Chumlyakov’s work is supported by a Russian grant RFBR-02-03-32013.
PY - 2006/5
Y1 - 2006/5
N2 - We present an extensive set of experimental results on deformation behavior under external stress and thermal hysteresis behavior of FeNiCoTi shape memory alloys. The experiments spanned from temperatures where the martensite variant motion is responsible for shape changes to cases where stress-induced transformation from austenite to martensite occurred. A temperature hysteresis of the order of 130°C and recoverable strains approaching 3.5% were observed in these materials. These recoverable strain magnitudes far exceed previously reported values on FeNiCoTi alloys. We identify the role of increased slip resistance via aging as partially responsible for increased reversibility and increase in transformation strains. The relaxation of the stored energy due to presence of dislocations at austenite-martensite interfaces was identified with transmission electron microscopy studies, and this is the primary mechanism for large thermal hysteresis as well as the limiting factor in reversibility of the transformation. The changes in transformation temperatures and the hysteresis behavior in the presence of coherent precipitates were rationalized based on a thermodynamics based mechanics model.
AB - We present an extensive set of experimental results on deformation behavior under external stress and thermal hysteresis behavior of FeNiCoTi shape memory alloys. The experiments spanned from temperatures where the martensite variant motion is responsible for shape changes to cases where stress-induced transformation from austenite to martensite occurred. A temperature hysteresis of the order of 130°C and recoverable strains approaching 3.5% were observed in these materials. These recoverable strain magnitudes far exceed previously reported values on FeNiCoTi alloys. We identify the role of increased slip resistance via aging as partially responsible for increased reversibility and increase in transformation strains. The relaxation of the stored energy due to presence of dislocations at austenite-martensite interfaces was identified with transmission electron microscopy studies, and this is the primary mechanism for large thermal hysteresis as well as the limiting factor in reversibility of the transformation. The changes in transformation temperatures and the hysteresis behavior in the presence of coherent precipitates were rationalized based on a thermodynamics based mechanics model.
KW - Aging
KW - Austenite
KW - Ferromagnetic shape memory alloy
KW - Hysteresis
KW - Iron-based shape memory alloy
KW - Martensite
KW - Modeling
KW - Phase transformation
UR - http://www.scopus.com/inward/record.url?scp=32444432308&partnerID=8YFLogxK
U2 - 10.1016/j.mechmat.2005.05.024
DO - 10.1016/j.mechmat.2005.05.024
M3 - Article
AN - SCOPUS:32444432308
VL - 38
SP - 538
EP - 550
JO - Mechanics of materials
JF - Mechanics of materials
SN - 0167-6636
IS - 5-6
ER -