Details
| Original language | English |
|---|---|
| Pages (from-to) | 2231-2236 |
| Number of pages | 6 |
| Journal | Acta materialia |
| Volume | 56 |
| Issue number | 10 |
| Publication status | Published - Jun 2008 |
| Externally published | Yes |
Abstract
Stress-induced martensitic transformations are clarified in classes of NiMnGa alloys which undergo the stress-free, thermal-induced inter-martensite transformation austenite (A) ⇌ pre-martensite (PM) ⇌ martensite. This study implements a comprehensive experimental approach, including analysis of the strain-temperature and stress-strain response, which discloses stress-induced inter-martensite transitions. The evolution of the transitions is elucidated using in situ digital image correlation (DIC) measurements of meso-scale strain fields. Under stress, this body of work unequivocally demonstrates that the transformation path becomes A ⇌ PM ⇌ I ⇌ 10M. The I-phase is an intermediate stress-induced martensite with a modulation period between three and five-layers. Owing to the intermediate transition, the thermal hysteresis in the strain-temperature response is tiny (<10 °C) compared with the hysteresis (32 °C) for A ⇌ 10M. The differential hysteresis levels are rationalized based on a thermo-mechanical formulation. Meso-scale DIC measurements quantify inter-martensite strain levels, which are indistinguishable from macro-scale stress-strain and strain-temperature responses.
Keywords
- Compression test, Digital image correlation, Metastable phases, Strain vs. temperature, Thermal hysteresis
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Ceramics and Composites
- Materials Science(all)
- Polymers and Plastics
- Materials Science(all)
- Metals and Alloys
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Acta materialia, Vol. 56, No. 10, 06.2008, p. 2231-2236.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Inter-martensite strain evolution in NiMnGa single crystals
AU - Hamilton, R. F.
AU - Sehitoglu, H.
AU - Aslantas, K.
AU - Efstathiou, C.
AU - Maier, H. J.
N1 - Funding Information: The work was supported by the NSF Grant No. CMS-0428428. The single crystals were obtained from Prof. Y. Chumlyakov of Tomsk State University.
PY - 2008/6
Y1 - 2008/6
N2 - Stress-induced martensitic transformations are clarified in classes of NiMnGa alloys which undergo the stress-free, thermal-induced inter-martensite transformation austenite (A) ⇌ pre-martensite (PM) ⇌ martensite. This study implements a comprehensive experimental approach, including analysis of the strain-temperature and stress-strain response, which discloses stress-induced inter-martensite transitions. The evolution of the transitions is elucidated using in situ digital image correlation (DIC) measurements of meso-scale strain fields. Under stress, this body of work unequivocally demonstrates that the transformation path becomes A ⇌ PM ⇌ I ⇌ 10M. The I-phase is an intermediate stress-induced martensite with a modulation period between three and five-layers. Owing to the intermediate transition, the thermal hysteresis in the strain-temperature response is tiny (<10 °C) compared with the hysteresis (32 °C) for A ⇌ 10M. The differential hysteresis levels are rationalized based on a thermo-mechanical formulation. Meso-scale DIC measurements quantify inter-martensite strain levels, which are indistinguishable from macro-scale stress-strain and strain-temperature responses.
AB - Stress-induced martensitic transformations are clarified in classes of NiMnGa alloys which undergo the stress-free, thermal-induced inter-martensite transformation austenite (A) ⇌ pre-martensite (PM) ⇌ martensite. This study implements a comprehensive experimental approach, including analysis of the strain-temperature and stress-strain response, which discloses stress-induced inter-martensite transitions. The evolution of the transitions is elucidated using in situ digital image correlation (DIC) measurements of meso-scale strain fields. Under stress, this body of work unequivocally demonstrates that the transformation path becomes A ⇌ PM ⇌ I ⇌ 10M. The I-phase is an intermediate stress-induced martensite with a modulation period between three and five-layers. Owing to the intermediate transition, the thermal hysteresis in the strain-temperature response is tiny (<10 °C) compared with the hysteresis (32 °C) for A ⇌ 10M. The differential hysteresis levels are rationalized based on a thermo-mechanical formulation. Meso-scale DIC measurements quantify inter-martensite strain levels, which are indistinguishable from macro-scale stress-strain and strain-temperature responses.
KW - Compression test
KW - Digital image correlation
KW - Metastable phases
KW - Strain vs. temperature
KW - Thermal hysteresis
UR - http://www.scopus.com/inward/record.url?scp=43449118673&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2008.01.007
DO - 10.1016/j.actamat.2008.01.007
M3 - Article
AN - SCOPUS:43449118673
VL - 56
SP - 2231
EP - 2236
JO - Acta materialia
JF - Acta materialia
SN - 1359-6454
IS - 10
ER -