Cheminform is a weekly abstracting service, delivering concise information at a glance that was extracted from about 200 leading journals. Although the degree of shape recovery decreases with an increase in the volume fraction of the. Offstoichiometric ni2mnga ferromagnetic shape memory alloys undergo a martensitic transformation mt from the l21 cubic phase to a martensitic crystal lattice consisting, in the majority of cases, of a periodic stacking sequence of nearly closedpacked planes with periodicity of 5, 7 or 2 planes, denoted as 10m five layered tetragonal, 14m seven layered orthorhombic and 2m non. A research group elucidated the mechanism of structural phase transition shown in ferromagnetic shape memory alloys for the first time, using hard xray photoelectron spectroscopy hxpes at the large synchrotron radiation facility spring8 and a computational technique, socalled, a. As actuators, these materials offer high energy density, large stroke, and high bandwidth.
Development of coniga ferromagnetic shape memory alloys. Numerical study of the microstructure in ferromagnetic. Magnetic properties of the ferromagnetic shape memory alloys. The curie point of nimnga alloys is below 100 c, which is a too low temperature for some applications. The underlying mechanisms responsible for the giant magnetic or mechanical fieldinducedstrains in ferromagnetic shape memory alloys are briefly discussed based on a phenomenological approach. Magnetic shape memory msm alloys take a unique position within the class of smart materials due to their outstanding strain up to 10% obtained in a moderate magnetic field. We study the complex crystal structure and variant configuration in freestanding single. Ferromagnetic shape memory alloyschallenges, applications. The aim of the conference is to generate an overview of worldwide research and development in the field of magnetic shape memory alloys and related phenomena. Structural, thermal and magnetic characterization of nimnga ferromagnetic shape memory alloys. The alloys of this system within the composition range ni 3045 at. Ferromagnetic ironpalladium shape memory alloys shape memory sm alloys are materials that return to a previous shape after thermal treatment.
Occurrence of ferromagnetic shape memory alloys invited. Several heusler and intermetallic alloys have been studied in connec tion with this property. Ferromagnetic shape memory effects in an iron palladium alloy. The recognition that a reversible domain reorientation in a magnetic field will cause a large magnetostrictive. Due to the unique combination of large displacements and fast mechanical response, fsma offer prospects for novel applications that make use of new mechanism for converting between magnetic and mechanical energies. Magnetic shape memory alloys msmas have the unique ability to change their shape within a magnetic field, or in the presence of stress and a change in temperature. In the assolidified state their martensite start temperatures vary in the range 20 c ferromagnetic shape memory alloys ferromagnetic shape memory alloys fsmas officially became recognized as a new class of active materials when a 0. Ferromagnetic shape memory alloys fsma constitute a subgroup of shape memory alloys sma that also exhibit a ferromagnetic behavior. The mechanism responsible for the large strain of msm alloys is the socalled magnetically induced reorientation mir. Phase diagram of fedoped nimnga ferromagnetic shape. Emphasis will be given to fundamental studies expanded to the related fields and the practical utility of ferromagnetic shape memory alloys fsmas.
The perspectives of the ferromagnetic shape memory alloy are also described. Therefore, msm alloys can be also activated thermally, like thermal shape memory alloys see, for instance, nickeltitanium alloys. Magnetocaloric effect and its relation to shapememory. As it can be seen, the appropiate landau op for the squaretorectangular transition is the deviatoric strain e 2. They show magnetic fieldinduced strains at room temperature greater than any electrostrictive, magnetostrictive or piezoelectric material, and faster frequency response than temperature driven shape memory alloys. The magnetic shape memory effect can be used to design actuators, where.
What is a shape memory alloy sma first order structural transformation by growth of a lower symmetry martensitic phase from the higher symmetry cubic. Promising ferromagnetic nicoal shape memory alloy system. Shape memory alloys smas are a heterogeneous class of metal alloys. Magnetic shape memory alloys as smart materials for micro. Among ferromagnetic shape memory alloys fsmas, coniga ternary alloys have attracted great attention due to their high curie and martensitic transformation temperatures as well as improved ductility. Ferromagnetic shape memory effects in an iron palladium. In the low temperature phase of these alloys, 90 magnetic domain walls are simultaneously elastic twin boundaries. The nimnga compound is of both technological and scientific interest, due to the presence of a ferromagnetic shape memory effect. Ferroic cooling systems were examined using niti and nimninco. Ferromagnetic shape memory alloys fsmas are the novel materials exhibiting shape memory effect sme and magnetism simultaneously. Shape memory alloys shape memory alloys are alloys which undergo a reversible martensitic transformation. Fundamental investigation of ferromagnetic shape memory. This companion effect, which coexist with the actuation, can be useful for the design of displacement, speed or.
Pdf observation of fieldinduced reverse transformation. The magnetic shape memory effect is a consequence of the coupling between magnetism and structure in ferromagnetic alloys undergoing a martensitic transformation. The fundamental aspect is illustrated by experimental data related to the lattice instability and composition dependence of magnetization alongside literature results. Hiroshima university tohoku university national institute for materials science tohoku gakuin university. Highfrequency performance of ferromagnetic shape memory alloys. Pdf ferromagnetic shape memory nifega alloy foams for.
A shape memory alloy is an alloy that can be deformed when cold but returns to its predeformed remembered shape when heated. Nimnx x in, sn, sb alloys, another important ferromagnetic shape memory alloy family, attracted attention of the scientific society since. Pdf on mar 9, 2020, muhammad imran and others published ferromagnetic shape memory nifega alloy foams for elastocaloric cooling find, read and cite all the research you need on researchgate. First elucidation of mechanism of shape memory effect. Ferromagnetic shape memory alloys fsmas like nimnga have attracted significant attention over the last few years. Memory alloys, cheminform on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Conial alloys have several advantages such as cost efficiency and workability, this alloy system is considered as being a new type of ferromagnetic shape memory alloys fsmas. Ferromagnetic shape memory alloys fmsmas have been received an increasing attraction due to their multifunctional properties 1,2, i. Magnetic shape memory alloy introduction, properties and. Ferromagnetic shape memory alloys indian academy of sciences. These properties make fsmas potential candidates for the new generation of actuators. Magnetic heusler alloys which undergo a martensitic transition display interesting functional properties.
Jan 15, 2014 magneticfield induced reorientation, or the magnetic shape memory effect, is defined as the magneticfieldinduced rearrangement of ferromagnetic twinned martensite microstructure along with a large macroscopic deformation. Fsma are considered as a strong candidate for fast responsive actuator material with higher strength. Ferromagnetic shape memory alloys fsma have the unique capability to exhibit the thermoelastic martensitic transformation and rearrangement of martensitic variants by applying a magnetic filed. Design of ferromagnetic shape memory alloy composites. It is amorphous noncrystalline, unlike many other ferromagnets. Ferromagnetic ironpalladium shape memory alloys johnson. Numerical study of the microstructure in ferromagnetic shape. It has a cubic l21 heusler structure space group fm 3m with the lattice parameter a. Magnetic shape memory alloys msmas, also called ferromagnetic shape memory alloys fsma, are particular shape memory alloys which produce forces and deformations in response to a magnetic field.
It may also be called memory metal, memory alloy, smart metal, smart alloy, or muscle wire. Observation of fieldinduced reverse transformation in ferromagnetic shape memory alloy ni50mn36sn14 article pdf available in applied physics letters 88. Characterization of shape memory alloys via transmission. Since the last years, other ferromagnetic shape memory alloys fsma, i. Two ferromagnetic shape memory alloys, fe 70 pd 30 and fepdpt thin films, were structurally and chemically investigated at the nanoscale by tem, including in situ measurements for evaluating specific phase transformations. This material combines the properties of ferromagnetism with those of a thermoelastic martensitic transformation, thus denoted as a ferromagnetic shape memory alloy fsma. Highfrequency performance of ferromagnetic shape memory. In effect, they undergo a phase transformation from a htgh temperature, strong, austenite structure to a low. Topics include ferromagnetic shape memory alloys, convection in weld pools under. The fundamental aspect is illustrated by experimental data related to the lattice instability and composition dependence of magnetization. Shape memory sm alloys are materials that return to a previous shape after thermal treatment. Msmas have been widely investigated in the past decade due to their ability to demonstrate large magnetic field induced strain and higher frequency response than conventional shape memory alloys smas. Calorimetric and ac susceptibility measurements have been carried out in order to study the magnetic and structural transformation properties.
Fundamental investigation of ferromagnetic shape memory alloys. In the martensite form the material can be deformed, but on heating. First, the transformation can be second order, and second, it can be of. The two most prevalent shape memory alloys are copperaluminiumnickel and nickeltitanium, but smas can also be created by alloying zinc, copper, gold and iron. Magnetic tweed contrast in ferromagnetic shape memory alloys.
T1 ferromagnetic shape memory effects in an iron palladium alloy. Magnetomechanical behavoirs of ferromagnetic shape. Apart from the theoretical challenge of understanding. The mechanism responsible for the large strain of msm alloys is the socalled magnetically induced reorientation mir, and is sketched in the figure. Barman ugcdae consortium for scientific research, indore th 77 annual meeting of indian academy of sciences, november 1820, 2011, physical research laboratory, ahmedabad. Bright building 3141 tamu, college station, tx 778433141 usa abstract a thermodynamically consistent phenomenological model is presented which captures the ferromagnetic shape. Ibrahim karaman the utilization of ferromagnetic shape memory alloys fsmas in small scale devices has attracted considerable attention within the last decade. Modeling of ferromagnetic shape memory alloy based. Threedimensional constitutive model of martensite reorientation in nimnga ferromagnetic shape memory alloy. The shape memory effect of the fepd system was first found. In particular thin films are promising candidates for integration in microsystems. Msm devices promise innovative applications working at frequencies not achievable by. Structural, thermal and magnetic characterization of nimn. N2 this paper presents the results of an extensive series of experiments conducted on fe70pd30 using a recently developed apparatus, the magnetomechanical testing machine.
Ferromagnetic shape memory alloy how is ferromagnetic shape. International conference on martensitic transformations. Magnetic iron is used in power generation and distribution, nanowires and shapememory alloys. This paper reports recent results obtained using a new type of smart material called. Phenomenological modeling of ferromagnetic shape memory. Phase diagram of fedoped nimnga ferromagnetic shapememory. Magnetic tweed contrast in ferromagnetic shape memory. Although ironbased and copperbased smas, such as femnsi, cuznal and cualni, are commercially available and cheaper than niti, nitibased smas are preferable for most applications due to their stability and practicability. In 1996, ni2mnga alloy was found to generate a strain of 0. Ferromagnetic shape memory alloys undergo the usual shape memory effect by changing temperature.
We have studied the effect of fe addition on the structural and magnetic transitions in the magnetic shape memory alloy nimnga by substituting systematically each atomic species by fe. The thermal shape memory effect has been obtained in these materials, too. Recently, however, it was found that the conversion of variants can also be promoted by the application of a magnetic field to induce the martensitic state in ferromagnetic ni 2 mnga shape memory alloys. Iron is another transition metal and has a curie temperature of 1043 k. However, ni2mnga alloy is very brittle liang et al. Introduction r ecently, ferromagnetic shape memory alloys fsmas attract strong attention as a fast responsive actuator material. Journal of the mechanics and physics of solids in revision. Pdf ferromagnetic shape memory alloys, exhibiting large recoverable strain. Magnetic shape memory alloys magnetically induced martensite mim magnetically induced reorientation mir requirements for actuation exotic materials.
Pdf investigation on ferromagnetic shape memory alloys. Besides the wellknown superelasticity and shape memory effect, nimnga fsmas can exhibit large. Magnetic shape memory alloy msma which is an alloy of. The magnetic shapememory effect is a consequence of the coupling between magnetism and structure in ferromagnetic alloys undergoing a martensitic transformation. Ferromagnetic shape memory alloys are wellknown to exhibit short response time and large reversible strains owing to high stability of ferromagnetic martensite, modulated structure, high magnetocrystalline anisotropy mca and high saturation magnetization. What makes these materials attractive as actuators is their high energy density, large stroke, and high bandwidth. Send me an email if you would like a pdf version of any of my recent papers.
It is also possible that they undergo large changes of shape by applying a magnetic field. Change in resistance if the element is fully elongated or compressed. Among these alloys, ni2mnga is the most familiar alloy 1. Apr 25, 2016 ferromagnetic shape memory alloys fsma constitute a subgroup of shape memory alloys sma that also exhibit a ferromagnetic behavior. Multiferroic shapememory alloys that exhibit both ferroelastic and ferromagnetic properties have recently attracted much attention. Variable structure control of a ferromagnetic shape memory. Of ferromagnetic shape memory alloys the underlying mechanisms responsible for the giant magnetic or mechanical fieldinducedstrains in the nimnga ferromagnetic shape memory alloys are briefly discussed. A new ferromagnetic shape memory alloy system sciencedirect. Numerical study of the microstructure in ferromagnetic shape memory alloys jonathan f. For high temperature applications, high t c is also an important requirement. Giant magnetostriction in ferromagnetic shapememory alloys. Phenomenological modeling of ferromagnetic shape memory alloys. Shape memory alloys smas are a very promising class of metallic materials that display interesting nonlinear properties, such as pseudoelasticity pe, shape memory effect sme and damping capacity, due to high mechanical hysteresis and internal friction.
Characterization and properties of ferromagnetic shape memory. Phenomenological modeling of ferromagnetic shape memory alloys bj. Emphasis will be given to fundamental studies expanded to the related fields and the practical utility of. The fundamental aspect is illustrated by the experimental results related to the lattice, mechanical and magnetic instabilities in the prototype nimn. Nimnga alloys are a kind of ferromagnetic shape memory alloys fsmas and have received more and more attention owing to their potential applications in sensors, actuators and energy harvesting applications soderberg et al. In order to reduce the evaporation of manganese du ring the crystal growth, the furnace is backfilled to a positive pressure of 6. Barman ugcdae consortium for scientific research, indore th 77 annual meeting of indian academy of sciences, november 18. Ferromagnetic shape memory alloys fsma have the unique capability to exhibit the thermoelastic martensitic transformation and rearrangement of martensitic. They belong to the family of socalled smart materials and are futuregeneration materials that are likely to be useful in cuttingedge technologies. Orthopaedic applications of ferromagnetic shape memory.
Mnga ferromagnetic shape memory alloys are briefly discussed. In effect, they undergo a phase transformation from a high temperature, strong, austenite structure to a low temperature, weaker, martensite structure. Above the temperature at which these alloys undergo a near second order martensitic. This was only a fraction of the 6 to 7% strain ultimately attainable by field. Shape memory alloy effect in addition to a shape change caused by the application of a magnetic field, an additional shape change is caused by temperature. One of the initial topics was the change of the martensite start temperature as a function of the magnetic field in ferrous alloys, not necessarily fmsmas. Applications of shape memory alloys for neurology and. Modification of microstructure and shape of solid materials by an external magnetic field. Ferromagnetic shape memory alloys fsmas like nimnga have attracted significant attention over the past few years. Ferromagnetic shape memory alloy fsma composites composed of a ferromagnetic material and a shape memory alloy sma. In these materials large reversible strains can be magnetically induced by the rearrangement of the martensitic twinvariant structure.