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Title: Mechanical behavior and microstructural analysis of NiTi-40Au shape memory alloys exhibiting work output above 400 °C

Authors:
ORCiD logo; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1413799
Grant/Contract Number:
SC0001258
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Intermetallics
Additional Journal Information:
Journal Volume: 86; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-12-18 06:23:08; Journal ID: ISSN 0966-9795
Publisher:
Elsevier
Country of Publication:
United Kingdom
Language:
English

Citation Formats

Casalena, Lee, Bigelow, Glen S., Gao, Yipeng, Benafan, Othmane, Noebe, Ronald D., Wang, Yunzhi, and Mills, Michael J. Mechanical behavior and microstructural analysis of NiTi-40Au shape memory alloys exhibiting work output above 400 °C. United Kingdom: N. p., 2017. Web. doi:10.1016/j.intermet.2017.03.005.
Casalena, Lee, Bigelow, Glen S., Gao, Yipeng, Benafan, Othmane, Noebe, Ronald D., Wang, Yunzhi, & Mills, Michael J. Mechanical behavior and microstructural analysis of NiTi-40Au shape memory alloys exhibiting work output above 400 °C. United Kingdom. doi:10.1016/j.intermet.2017.03.005.
Casalena, Lee, Bigelow, Glen S., Gao, Yipeng, Benafan, Othmane, Noebe, Ronald D., Wang, Yunzhi, and Mills, Michael J. Sat . "Mechanical behavior and microstructural analysis of NiTi-40Au shape memory alloys exhibiting work output above 400 °C". United Kingdom. doi:10.1016/j.intermet.2017.03.005.
@article{osti_1413799,
title = {Mechanical behavior and microstructural analysis of NiTi-40Au shape memory alloys exhibiting work output above 400 °C},
author = {Casalena, Lee and Bigelow, Glen S. and Gao, Yipeng and Benafan, Othmane and Noebe, Ronald D. and Wang, Yunzhi and Mills, Michael J.},
abstractNote = {},
doi = {10.1016/j.intermet.2017.03.005},
journal = {Intermetallics},
number = C,
volume = 86,
place = {United Kingdom},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.intermet.2017.03.005

Citation Metrics:
Cited by: 1work
Citation information provided by
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  • Magnetic shape memory alloys (MSMAs) have recently been developed into a new class of functional materials that are capable of magnetic-field-induced actuation, mechanical sensing, magnetic refrigeration, and energy harvesting. In the present work, the magnetic field-induced martensitic phase transformation (FIPT) in Ni{sub 45}Mn{sub 36.5}Co{sub 5}In{sub 13.5} MSMA single crystals is characterized as a new actuation mechanism with potential to result in ultra-high actuation work outputs. The effects of the applied magnetic field on the transformation temperatures, magnetization, and superelastic response are investigated. The magnetic work output of NiMnCoIn alloys is determined to be more than 1 MJ m{sup -3} permore » Tesla, which is one order of magnitude higher than that of the most well-known MSMAs, i.e., NiMnGa alloys. In addition, the work output of NiMnCoIn alloys is orientation independent, potentially surpassing the need for single crystals, and not limited by a saturation magnetic field, as opposed to NiMnGa MSMAs. Experimental and theoretical transformation strains and magnetostress levels are determined as a function of crystal orientation. It is found that [111]-oriented crystals can demonstrate a magnetostress level of 140 MPa T{sup -1} with 1.2% axial strain under compression. These field-induced stress and strain levels are significantly higher than those from existing piezoelectric and magnetostrictive actuators. A thermodynamical framework is introduced to comprehend the magnetic energy contributions during FIPT. The present work reveals that the magnetic FIPT mechanism is promising for magnetic actuation applications and provides new opportunities for applications requiring high actuation work-outputs with relatively large actuation frequencies. One potential issue is the requirement for relatively high critical magnetic fields and field intervals (1.5-3 T) for the onset of FIPT and for reversible FIPT, respectively.« less
  • It is now well-known that the two-way memory effect (TWME) of shape memory alloys is obtained after a thermomechanical cycling called training. Although this point is well-admitted, many controversies still subsist on the physical origin of this two-memory effect. The explanations of the development of the TWME which are often given are either the presence after training of a low proportion of local stabilized martensite in the parent phase or the presence after training of an internal stress field in the material. Recently, in a systematic study of the two-way memory effect obtained by thermomechanical training cycles under homogeneous tensilemore » constant load, Stalmans et. al. disproved these two previous explanations. Following the study, the most important effect of the dislocation arrays which are introduced during the training is not to develop internal stresses but rather to give rise to a microstructural anisotropy inducing a thermodynamic anisotropy. It means that after training, the crystallographically equivalent martensite variants are no more thermodynamically equivalent. The present paper describes some experimental results obtained by the homogeneous simple shear training of a NiTi shape memory alloy. The experiments have been specifically designed to give new comprehension elements on the existence and the nature of the thermodynamic anisotropy developed during training.« less
  • The shape memory effect is closely related to a martensitic phase transformation and the memory strain (the recoverable strain) is brought about by stress induced martensitic phase transformation or by reorientation of the martensite variants during stressing. Finally, the most favorably oriented martensite B19{prime} with respect to the stress transforms back to the high temperature phase B2. There is a lot of information concerning deformation behavior of annealed TiNi polycrystalline alloys as well as single crystals. This paper concentrates on the influence of work hardening and annealing on substructure characteristics and deformation behavior of TiNi alloys.
  • In situ synchrotron X-ray diffraction measurements are used to create two-dimensional maps of elastic strain and texture, averaged over a compact-tension specimen thickness, near a crack tip in a martensitic NiTi alloy. After fatigue crack propagation, the material ahead of the crack and in its wake exhibits a strong texture, which is eliminated by subsequent shape-memory heat treatment, indicating that this texture is due to detwinning, the main deformation mechanism of NiTi. Upon subsequent application of a static tensile stresses, the highly textured zone reappears and grows around the crack tip as the applied stress is increased. At the highestmore » applied stress intensity of 35MPam1/2, large tensile strains are measured ahead of the crack tip and considerable elastic anisotropy is observed. This detwinning zone is similar to the plastic zone produced by dislocation slip present around cracks in other metals. The texture in this zone is not significantly altered after mechanical unloading, despite the development of substantial triaxial compressive residual strains in this zone.« less
  • In the expanding world of small scale energy harvesting, the ability to combine thermal and mechanical harvesting is growing ever more important. Here, we demonstrate the feasibility of using ZnO nanowires to harvest both mechanical and low-quality thermal energy in simple, scalable devices. These devices were fabricated on kapton films and used ZnO nanowires with the same growth direction to assure alignment of the piezoelectric potentials of all of the wires. Mechanical harvesting from these devices was demonstrated using a periodic application of force, modeling the motion of the human body. Tapping the device from the top of the devicemore » with a wood stick, for example yielded an Open Circuit Voltage (OCV) of 0.2 - 4 V, which is in an ideal range for device applications. In order to demonstrate thermal harvesting from low quality heat sources, a commercially available Nitinol (Ni-Ti alloy) foil was attached to the nanowire piezoelectric device to create a compound thermoelectric. When bent at room temperature and then heated to 50°C, the Nitinol foil was restored to its original flat shape, which yielded an output voltage of nearly 1 V from the ZnO nanowire device.« less