Abstract
Ni-Mn-Ga alloys can exhibit a thermoelastic phase transformation near room temperature, which is associated with the shape-memory effect (i.e., temperature-induced strain recovery after twinning) or superelasticity (i.e., strain recovery after a stress-induced phase transformation). This work uses a synchrotron X-ray transmission technique to investigate texture induced by applying magnetic fields during the phase transformation in polycrystalline Ni2MnGa. Synchrotron X-ray radiation is ideally suited for such investigations since the measurements are representative of twinning in the bulk, in contrast with measurements from conventional X-ray sources that represent surface measurements affected by surface relaxation. Magnetic texturing of polycrystalline Ni2MnGa, by cooling through the phase-transformation in the presence of a magnetic field, has potential to lead to polycrystalline materials with more compatible field-induced strains and hence increased twin boundary mobility upon application of a magnetic and/or stress field.
Original language | English |
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Pages (from-to) | [d]EE2.7.1-EE2.7.6 |
Journal | Materials Research Society Symposium - Proceedings |
Volume | 678 |
Publication status | Published - 2001 |
Event | Applications of Synchrotron Radiation Techniques to Materials Science VI - San Francisco, CA, United States Duration: 16 Apr 2001 → 20 Apr 2001 |
Funding
The diffraction experiments were performed at the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) Synchrotron Research Center at the Advanced Photon Source (APS), whose staff we acknowledge for technical support. DND-CAT is supported by the E.I. DuPont de Nemours, Dow Chemical Co., NSF (through Grant DMR-9304725) and the State of Illinois. Use of APS was supported by DOE Contract W-31-102-Eng-38. We also thank Professor D.N. Seidman (Northwestern University) and Dr. J. P. Quintana (DND-CAT) for useful discussions on twinning and instrumentation, respectively.
Funders | Funder number |
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E.I. DuPont de Nemours | |
National Science Foundation | DMR-9304725 |
U.S. Department of Energy | W-31-102-Eng-38 |
Dow Chemical Company |