Shape Memory Effect in Microsized Samples of Rapidly Quenched Ferromagnetic Alloy Ni-Mn-Ga

2012 ◽  
Vol 190 ◽  
pp. 295-298 ◽  
Author(s):  
K. Akatyeva ◽  
V. Afonina ◽  
F. Albertini ◽  
S. von Gratowski ◽  
A. Irzhak ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Magnetic Field Effect ◽  
Rapid Quenching ◽  
Thermomechanical Properties

The melt spun ribbons of ferromagnetic shape-memory alloy (FSMA) Ni53Mn24Ga23 have been prepared by rapid quenching. Thermomechanical properties have been studied by multi-point technique and perfect shape memory effect (SME) observed. The magnetic field effect on thermomechanical behavior was studied by placing multi-point press into Bitter magnet. A giant (1.2%) bending strain, due to magnetic field-induced martensitic transformation (magnetic-field-induced SME), has been observed at a constant temperature T= 56 °C in a field of 6 T. At least 80% of martensitic transformation reversibly induced by the external field was observed experimentally. Submicron sized samples of the alloy with thicknesses down to 300 nm have been milled by focused ion beam (FIB) technique. The deformation behavior of these samples was studied by Omniprobe micromanipulator in the vacuum chamber of FIB device. The SME response was tested in situ by heating the samples with a semiconductor laser. Strong two-way SME was observed due to bending strains of the samples under study.

Shape memory effect due to magnetic field-induced thermoelastic martensitic transformation in polycrystalline Ni–Mn–Fe–Ga alloy

2001 ◽  
Vol 291 (2-3) ◽  
pp. 175-183 ◽  
Author(s):  
A.A. Cherechukin ◽  
I.E. Dikshtein ◽  
D.I. Ermakov ◽  
A.V. Glebov ◽  
V.V. Koledov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Thermoelastic Martensitic Transformation

Martensitic Transformation and Shape Memory Effect of Ni53.25Mn21.75Ga25 Ferromagnetic Shape Memory Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 1504-1507
Author(s):  
Hai Bo Wang ◽  
Shang Shen Feng ◽  
Pei Yang Cai ◽  
Yan Qiu Huo
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Parent Phase ◽  
Transformation Strain ◽  
Scanning Calorimetry ◽  
Reversible Transformation ◽  
Ferromagnetic Shape Memory

The martensitic transformation, crystalline structure, microstructure and shape memory effect of the Ni53.25Mn21.75Ga25 (at.%) alloy are investigated by means of Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD), Transmission Electron Microscope (TEM) and the standard metal strain gauge technique. The XRD results showed that the Ni53.25Mn21.75Ga25 alloy is composed of cubic parent phase at room temperature. TEM observation proved that the typical twin martensite is tetragonal structure and tweed-like contrast which is typical image for the parent phase. A large reversible transformation strain, about 0.54%, is obtained in this undeformed polycrystalline alloy due to martensitic transformation and its reverse transformation. This transformation strain is also increased to 0.65% by the external magnetic field. It is believed that the effect of the magnetic field on the preferential orientation of martensitic variants increases the transformation strain.

scholarly journals Эффект памяти формы в микроразмерном образце сплава Гейслера Ni-Mn-Ga-Cu

2020 ◽  
Vol 62 (6) ◽  
pp. 860
Author(s):  
А.В. Маширов ◽  
А.В. Иржак ◽  
А.В. Кошелев ◽  
Н.В. Андреев ◽  
К.А. Колесов ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Elastic Deformation ◽  
Heusler Alloy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Residual Deformation ◽  
Martensitic Phase ◽  
Maximum Value

The paper demonstrates the shape memory effect in a ferromagnetic micro-sample of Heusler alloy Ni50Mn18.5Ga25Cu6.5. The microsample was made using focused ion beam technology and has an overall size of 23 × 1.28 × 4 μm. It was found that the value of elastic deformation in the martensitic phase exceeds the value of the shape memory effect, which is based on residual deformation due to twinning. The maximum value of the shape memory effect was 3.4%.

Martensitic transformation and shape memory effect under magnetic field for Ni2MnGa sputtered films containing iron

2008 ◽  
Vol 481-482 ◽  
pp. 275-278 ◽  
Author(s):  
Makoto Ohtsuka ◽  
Hiroyuki Katsuyama ◽  
Minoru Matsumoto ◽  
Toshiyuki Takagi ◽  
Kimio Itagaki
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Sputtered Films

Thermoelastic martensitic transition and shape memory effect in Ti2NiCu alloy at micro- and nanoscale

2021 ◽  
Author(s):  
P.V. Lega
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Focused Ion Beam ◽  
Fundamental Problem ◽  
Ion Beam ◽  
Deep Understanding ◽  
Original Method ◽  
Practical Significance ◽  
Martensitic Transition

Problem. An important fundamental problem in condensed matter physics is the study of the physical properties of various materials at the nanoscale size. A deep understanding of size effects is necessary when studying multifunctional solid materials with phase transitions and giant effects, such as magnetocaloric, elastocaloric, shape memory effect (SME). Goal. Direct experimental study of the manifestation of the thermoelastic martensitic transition and the accompanying SME in the Ti2NiCu alloy at the nanoscale in transmission electron microscope (TEM). Result. For the first time in a TEM during heating and cooling, the observed SME in nanocomposite amorphous-crystalline Ti2NiCu samples while observing the evolution of the structure of martensitic twins and the shape of changes. Investigations are carried out on wedge-shaped samples with variable thickness from 200 to 20 nm, in the form of a composite bimetallic nano-actuator, using the original method of local etching and polishing with a focused ion beam (FIB). Practical significance. These findings open the pathway for size limit indications and regime modulations where the alloy-based nanomechanical devices can be tuned to operate more efficiently.

Martensitic transformation, ductility, and shape-memory effect of polycrystalline Ni56Mn25 –xFexGa19alloys

2005 ◽  
Vol 96 (8) ◽  
pp. 843-846 ◽  
Author(s):  
Yunqing Ma ◽  
Lihong Xu ◽  
Yan Li ◽  
Chengbao Jiang ◽  
Huibin Xu ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect

scholarly journals Fabrication and Shape Memory Characteristics of Highly Porous Ti-Nb-Mo Biomaterials

2017 ◽  
Vol 62 (2) ◽  
pp. 1367-1370 ◽  
Author(s):  
Y.-W. Kim ◽  
T.W. Mukarati
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Differential Scanning Calorimetric ◽  
Porous Scaffolds ◽  
High Porosity ◽  
Porous Ti ◽  
Human Body Temperature ◽  
Rapidly Solidified

AbstractNon-toxic Ti-Nb-Mo scaffolds were fabricated by sintering rapidly solidified alloy fibers for biomedical applications. Microstructure and martensitic transformation behaviors of the porous scaffolds were investigated by means of differential scanning calorimetric and X-ray diffraction. Theα″–βtransformation occurs in the as-solidified fiber and the sintered scaffolds. According to the compressive test of the sintered scaffolds with 75% porosity, they exhibit good superelasticity and strain recovery ascribed to the stress-induced martensitic transformation and the shape memory effect. Because of the high porosity of the scaffolds, an elastic modulus of 1.4 GPa, which matches well with that of cancellous bone, could be obtained. The austenite transformation finishing temperature of 77Ti-18Nb-5Mo alloy scaffolds is 5.1°C which is well below the human body temperature, and then all mechanical properties and shape memory effect of the porous 77Ti-18Nb-5Mo scaffolds are applicable for bon replacement implants.

scholarly journals Effect of Thermomechanical Cycling on Martensitic Transformation and Shape Memory Effect in 304 Austenitic Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 901
Author(s):  
Jie Chen ◽  
Yonghao Zhang ◽  
Jiqiang Ge ◽  
Huabei Peng ◽  
Shuke Huang ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Austenitic Steel ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Annealing Temperature ◽  
Cycle Number ◽  
Thermomechanical Cycling ◽  
Ε Martensite ◽  
Optimum Annealing Temperature

To improve the shape memory effect (SME) of 304 austenitic steel effectively and efficiently, thermomechanical cycling, comprising deformation at room temperature and annealing, was applied. The influences of cycle number and annealing temperature on the SME and microstructures in 304 austenitic steel were investigated by light microscope (LM), X-ray diffraction (XRD), and transmission electron microscope (TEM). The shape recovery ratio was remarkably improved from 16% to 40% after two thermomechanical cycles. The optimum annealing temperature was 833 K in the process of thermomechanical cycling. The improved SME by thermomechanical cycling was mainly related to stress-induced ε martensite rather than stress-induced α’ martensite. The reason is that thermomechanical cycling can not only promote the occurrence of the stress-induced γ→ε martensitic transformation, but also suppress the subsequently stress-induced ε→α′ transformation.

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