Influence of Magnetic Field and Stress on Large Magnetic Shape Memory Effect in Single Crystalline Ni-Mn-Ga Ferromagnetic Alloy at Room Temperature

2001 ◽  
Vol 373-376 ◽  
pp. 341-344 ◽  
Author(s):  
O. Heczko ◽  
Nadiya Glavatska ◽  
K. Ullakko ◽  
Valentin G. Gavriljuk
Keyword(s):  
Magnetic Field ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Room Temperature ◽  
Ferromagnetic Alloy ◽  
Magnetic Shape Memory ◽  
Single Crystalline

Shape Memory Effect in Fe-Pd Magnetic Shape Memory Alloy Thin Films

2010 ◽  
Vol 654-656 ◽  
pp. 2107-2110
Author(s):  
Jun Hyun Han ◽  
Tae Ahn ◽  
Hyun Kim ◽  
Kwang Koo Jee
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Stress Change ◽  
Composition Gradient ◽  
Cantilever Beams ◽  
Magnetic Shape Memory ◽  
Magnetic Shape Memory Alloy

The shape memory effect (SME) and magnetic shape memory effect (MSME) Fe-Pd thin film are using the film curvature method. The corresponding residual stress change due to theSME and MSME in Fe-Pd film is measuredduring thermal cycling and magnetic field changing. AFe-Pd thin film with a lateral composition gradient is deposited onto micromachined x7 cantilever beam arraysubstrate,such that each of the cantilever beams is coated with a film of different composition.There is abrupt stress change in only .1 at % Pd as the temperature of the film is cycled, and the corresponding stress change was measured as 0.16 GPa. The film with .4 at % Pd showsthe abrupt stress change at 0.7 Tesla, which means that the composition has the MSME.

Magnetic Shape Memory Effect in Ni-Mn-Ga Single Crystal

2016 ◽  
Vol 879 ◽  
pp. 738-743
Author(s):  
Oleg Heczko ◽  
Vít Kopecký ◽  
Jan Drahokoupil ◽  
Marek Vronka ◽  
Oleksiy Perevertov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
High Mobility ◽  
Type I ◽  
X Ray Diffraction ◽  
Magnetic Shape Memory ◽  
Twin Boundaries ◽  
Induced Structure

Magnetic shape memory effect is general name for several effects in which the most visible feature is huge strain induced by magnetic field. Magnetic field-induced structure reorientation (MIR) occurs due to motion of twin boundaries in single phase. As the magnetic field is a relatively weak force compared with mechanical stress, very high mobility of twin boundaries is crucial. Here we study the properties of martensite relevant for this effect using X-ray diffraction, optical and electron microscopy, magnetic observation and mechanical testing. In 10M modulated martensite, two types of mobile twin boundary (type I and type II) are observed with complex layered microstructures consisting of a hierarchy of twinning systems. We search for analogue with non-magnetic Cu-Ni-Al shape memory alloy.

scholarly journals Magnetic Properties and Microstructures of Rapidly Solidified FePd Alloy Ribbons

2008 ◽  
Vol 59 ◽  
pp. 24-29 ◽  
Author(s):  
Yoichi Kishi ◽  
Zenjiro Yajima ◽  
Teiko Okazaki ◽  
Yasubumi Furuya ◽  
Manfred Wuttig
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Coercive Force ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Room Temperature ◽  
Parent Phase ◽  
Diffraction Profile ◽  
Rapidly Solidified

It is well known that FePd alloys are effective as a magneto-thermoelastic actuator material, because they have large magnetostriction and shape memory effect. In order to use the alloys for a micro-actuator, magnetic properties and microstructures have been examined as for rapidly solidified Fe-29.6 at% Pd alloy ribbons. The ribbons exhibit a large magnetostriction at room temperature and good shape memory effect. Magnetostriction and coercive force of the ribbons markedly depend on the direction of the applied magnetic field. Maximum values of magnetostriction and coercive force are obtained at θ = 85 degree (θ is the angle between the magnetic field and the ribbon plane). Relief effects corresponding to the formation of FCT martensite variants are observed on the grains. X-ray diffraction profile at room temperature shows that FCT martensitic phase and FCC parent phase coexist in the ribbon. Dense striations are observed in the TEM bright field images of FCT martensite plates. Selected area electron diffraction patterns revealed the striations to be thin twins.

scholarly journals Room temperature magnetic shape-memory effect in strontium-doped lanthanum cobaltite single crystals

AIP Advances ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 095217
Author(s):  
A. Yokosuka ◽  
H. Kumagai ◽  
M. Fukuda ◽  
K. Ando ◽  
Y. Hara ◽  
...  
Keyword(s):  
Shape Memory ◽  
Single Crystals ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Room Temperature ◽  
Magnetic Shape Memory ◽  
Lanthanum Cobaltite

High performance shape memory effect in nitinol wire for actuators with increased operating temperature range

2014 ◽  
Vol 07 (05) ◽  
pp. 1450063 ◽  
Author(s):  
Riccardo Casati ◽  
Carlo Alberto Biffi ◽  
Maurizio Vedani ◽  
Ausonio Tuissi
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
High Performance ◽  
Room Temperature ◽  
Operating Temperature ◽  
Niti Wire ◽  
Shape Memory Actuators ◽  
Nitinol Wire ◽  
Operating Temperature Range

In this research, the high performance shape memory effect (HP-SME) is experimented on a shape memory NiTi wire, with austenite finish temperature higher than room temperature. The HP-SME consists in the thermal cycling of stress induced martensite and it allows achieving mechanical work higher than that produced by conventional shape memory actuators based on the heating/cooling of detwinned martensite. The Nitinol wire was able to recover about 5.5% of deformation under a stress of 600 MPa and to withstand about 5000 cycles before failure. HP-SME path increased the operating temperature of the shape memory actuator wire. Functioning temperatures higher than 100°C was reached.

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