Effects Of The Internal Magnetic Field On The Magneto Mechanical Properties Of Magnetic Shape Memory Alloys

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Effects of the Internal Magnetic Field on the Magneto-mechanical Properties of Magnetic Shape Memory Alloys

Author : Anthony Hobza
Publisher :
ISBN 13 :
Total Pages : 158 pages
Book Rating : 4.:/5 (12 download)

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Book Synopsis Effects of the Internal Magnetic Field on the Magneto-mechanical Properties of Magnetic Shape Memory Alloys by : Anthony Hobza

Download or read book Effects of the Internal Magnetic Field on the Magneto-mechanical Properties of Magnetic Shape Memory Alloys written by Anthony Hobza and published by . This book was released on 2017 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Shape memory alloys are a class of functional material which recover from large strains without permanent deformation. The strain is accommodated by the displacement of twin boundaries in the martensite phase. The shape memory alloy Ni-Mn-Ga is also ferromagnetic. Ni-Mn-Ga preferentially magnetizes along a certain crystallographic axis. This direction of easy magnetization changes across twin boundaries, such that the directions in neighboring twin domains are nearly perpendicular. The interaction of magnetic moments and interfaces including the crystal surface and twin boundary interfaces has a large role in the magnetization process of the material. The goal of this study is to characterize the relative influence of twin boundaries on the magnetization of the material, and the dependence of the magnetization on the twin domain microstructure. The torque on a single crystal specimen in a homogeneous external magnetic field was characterized with experimental methods. The torque is the negative first derivative of the magnetic energy as a function of angle between the specimen and magnetic field. The torque and magnetic energy strongly depends on the twin domain microstructure. For specimen with two twin boundaries at 3% strain in an external magnetic field of 50 mT, one twin microstructure required 1.7 times more torque to rotate than another twin microstructure. At fields above 100 mT, the torque was asymmetric depending on the direction the direction the sample was rotated. Numerical micromagnetic simulations were performed to gain a qualitative understanding of the difference in magnetization and magnetic energy in different twin microstructures. At low fields, the continuity of magnetization across the twin boundary results in one twin microstructure having completely saturated twin domains, while the other microstructures contained 180° magnetic domains. At larger fields, the asymmetry in torque was due to the angle of the twin boundary with the crystal surface. Both the dependence on magnetization and torque asymmetry are due to the internal magnetic field at the twin boundary. The interaction of magnetic moments across the twin boundary drives the internal magnetic field and magnetization. The twin domain microstructure can be manipulated to drive the magnetization process in order to optimize the performance of the material in a device. The role of the internal magnetic field and specimen magnetization is discussed regarding a low power strain sensing measurement technique."--Boise State University ScholarWorks.

Effects of Magnetic Domain and Twin Boundary Interactions on Magneto-mechanical Properties of Magnetic Shape Memory Alloys

Author : Medha Veligatla
Publisher :
ISBN 13 :
Total Pages : 142 pages
Book Rating : 4.:/5 (129 download)

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Book Synopsis Effects of Magnetic Domain and Twin Boundary Interactions on Magneto-mechanical Properties of Magnetic Shape Memory Alloys by : Medha Veligatla

Download or read book Effects of Magnetic Domain and Twin Boundary Interactions on Magneto-mechanical Properties of Magnetic Shape Memory Alloys written by Medha Veligatla and published by . This book was released on 2019 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Magnetic shape memory (MSM) alloys deform substantially when exposed to a magnetic field. This recoverable plastic deformation occurs through crystallographic twinning. Thereby the internal magnetic domain structure modulates the deformation mechanisms through the interaction of magnetic domains with twin boundaries. We study the meso scale magneto-structural interactions that affect the macroscopic material properties of MSM alloys. The study at the meso length scale is most effective as it allows for resolving interactions at magnetic domain wall width resolution with reasonable computing cost. We apply micromagnetics simulations to evaluate the evolution of magnetic domains, their interaction with twin boundaries, the distribution of magnetic energies, and semi-quantitatively assess the magneto-mechanical properties of MSM alloys. This dissertation addresses the following phenomena demonstrated by experimental findings: 1. The sample shape dependence of twin boundary propagation. The results from this study are useful to design actuators. Due to the sample shape, the demagnetization factor varies with the direction of the external magnetic field. Especially when the magnetic field is perpendicular to the long edge of the sample (high demagnetizing field), the magnetic energy intermittently increases with deformation (at low fields) which hinders twin boundary motion and results in gradual actuation. Whereas when the applied magnetic field is parallel to the long edge of the sample (lowest demagnetizing field), the energy decreases with deformation and the twin boundary moves instantaneously resulting in abrupt actuation. 2. Magnetic domain and twin boundary interactions that result in work hardening. This study addresses the monotonically increasing stress with ongoing deformation in fine twinned MSM alloys. Additional “vertical” magnetic domains form in densely twinned MSM alloys. The interaction of twin boundaries with these vertical magnetic domains results in magneto-elastic defects, which generate high local magneto-stresses. These interaction sites act as obstacles for twinning disconnections similar to coherent particles in precipitation-hardened aluminum alloys. Whereas in a low twin density MSM alloy, these magneto-stress concentrations are dilute and their effectiveness is reduced by the synergistic action of many twinning disconnections. 3. Effect of magnetic field inclination on mechano-electrical energy conversion. This study aids in evaluating the power harvesting capacity of MSM alloys. Using the concept of inverse magneto-plasticity (i.e. deformation-induced change of magnetization), experiments were performed to convert mechanical energy to electrical energy under a non-perpendicular bias magnetic field. The highest power output was obtained when the biased magnetic field was inclined with respect to the loading direction. The inclined magnetic field biases the magnetic domain structure such as to increase the magnetization component in loading direction. This increases the conversion rate from mechanical to electrical energy. When the MSM material accommodates the meso scale interactions between the magnetic and crystallographic structures, magnetic structures evolve with global and local spatial energy gradients and concentrations of magnetostress. These modulations hinder twin boundary mobility and determine the macroscopic magneto-mechanical properties of MSM alloys."--Boise State University ScholarWorks.

Magneto-thermo-mechanical Response and Magneto-caloric Effect in Magnetic Shape Memory Alloys

Author : Cengiz Yegin
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (813 download)

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Book Synopsis Magneto-thermo-mechanical Response and Magneto-caloric Effect in Magnetic Shape Memory Alloys by : Cengiz Yegin

Download or read book Magneto-thermo-mechanical Response and Magneto-caloric Effect in Magnetic Shape Memory Alloys written by Cengiz Yegin and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ni-Co-Mn-In system is a new type of magnetic shape memory alloys (MSMAs) where the first order structural and magnetic phase transitions overlap. These materials can generate large reversible shape changes due to magnetic-field-induced martensitic transformation, and exhibit magneto-caloric effect and magnetoresistance. Ni-Co-Mn-Sn alloys are inexpensive alternatives of the Ni-Co-Mn-In alloys. In both materials, austenite has higher magnetization levels than martensite. Fe-Mn-Ga is another MSMA system, however, whose magnetization trend is opposite to those of the Ni-Co-Mn-X (In-Sn) systems upon phase transformation. The MSMAs have attracted great interest in recent years, and their magnetic and thermo-mechanical properties need to be further investigated. In the present study, the effects of indium concentration, cooling, and annealing on martensitic transformation and magnetic response of single crystalline Ni-Co-Mn-In alloys were investigated. Increasing indium content reduced the martensitic transformation start (Ms) temperature, while increasing temperature hysteresis and saturation magnetization. Increasing annealing temperature led to an increase in the Ms temperature whereas annealing at 400 degrees C and 500 degrees C led to the kinetic arrest of austenite. Cooling after solution heat treatment also notably affected the transformation temperatures and magnetization response. While the transformation temperatures increased in the oil quenched samples compared to those in the water quenched samples, these temperatures decreased in furnace cooled samples due to the kinetic arrest. The possible reasons for the kinetic arrest are: atomic order changes, or precipitate formation. Shape memory and superelastic response, and magnetic field-induced shape recovery behavior of sintered Ni43Co7Mn39Sn11 polycrystalline alloys were also examined. The microstructural analysis showed the existence of small pores, which seem to increase the damage tolerance of the sintered polycrystalline samples. The recoverable transformation strain, irrecoverable strain and transformation temperature hysteresis increased with stress upon cooling under stress. Moreover, magnetic-field-induced strain due to the field-induced phase transformation was confirmed to be 0.6% at 319K. Almost perfect superelastic response was obtained at 343K. A magnetic entropy change of 22 J kg-1 K-1 were determined at 219K from magneto-caloric effect measurements which were conducted on annealed Ni43Co7Mn39Sn11 ribbons. Magnetic characteristics and martensitic transformation behavior of polycrystalline Fe-Mn-Ga alloys were also examined. Cast alloys at various compositions were undergone homogenization heat treatments. It was verified by magnetization measurements that the alloys heat treated at 1050 degrees C shows martensitic transformation. The heat treatment time was determined to be 1 day or 1 week depending on the compositions.

Magnetic Shape Memory Alloys

Author : Xuexi Zhang
Publisher : Springer Nature
ISBN 13 : 981166336X
Total Pages : 273 pages
Book Rating : 4.8/5 (116 download)

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Book Synopsis Magnetic Shape Memory Alloys by : Xuexi Zhang

Download or read book Magnetic Shape Memory Alloys written by Xuexi Zhang and published by Springer Nature. This book was released on 2021-11-14 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book systematically describes the fundamentals of Magnetic shape memory alloys (MSMAs), with an emphasis on low-dimensional structures such as foams, microwires and micro-particles. The respective chapters address basic concepts and theories, the fabrication of various architectures, microstructure tailoring, property optimization and cutting-edge applications. Taken together, they provide a clear understanding of the correlation between processing and the microstructural properties of MSMAs, which are illustrated in over two hundred figures and schematics. Given its scope and format, the book offers a valuable resource for a broad readership in various fields of materials science and engineering, especially for researchers, students and engineers.

Magneto-Mechanical Response in Ni-Mn-Ga Magnetic Shape Memory Alloys

Author :
Publisher :
ISBN 13 :
Total Pages : 46 pages
Book Rating : 4.:/5 (644 download)

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Book Synopsis Magneto-Mechanical Response in Ni-Mn-Ga Magnetic Shape Memory Alloys by :

Download or read book Magneto-Mechanical Response in Ni-Mn-Ga Magnetic Shape Memory Alloys written by and published by . This book was released on 2004 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is generally accepted that the large reversible, magnetic-field-induced strain observed in ferromagnetic shape memory alloys is due to the rearrangement of twin variants in the martensite by an applied magnetic field leading to an overall change of shape. The main thermodynamic driving force for twin boundary motion in the presence of a magnetic field is the high magnetocrystalline anisotropy of the low-symmetry martensitic phase. Low twin boundary energy, high magnetocrystalline anisotropy energy and saturation magnetization are some of the key factors for large magnetic field induced strain. In order to achieve optimum performance, thermomechanical and magnetic treatments are necessary. In this investigation, a systematic investigation is being carried out on single crystals of Ni-Mn-Ga alloys to determine the combined effects of composition and thermomagneto-mechanical treatments on the crystal structure of the martensitic phases and the magnetomechanical properties of the Ni-Mn-Ga alloys. Repeated mechanical and magnetic forces have been applied to the samples. The results demonstrate that prior history has strong influence on the twinning start stress and twinning strain. In addition, heat treatment of the materials seems to increase the amount of strain that can be obtained (e.g. increased from 3% to 6%). Moreover, there is indication that prior heat treatment may also affect the martensite crystal structure that is formed during cooling. A systematic investigation has also been carried out to determine the effect of temperature on the magneto-mechanical behaviour of the Ni-Mn-Ga alloys. Strong temperature dependence of the magnetic shape memory effect in a Ni47.8Mn27.5Ga24.7 alloy has been observed.

Handbook of Magnetic Materials

Author : K.H.J. Buschow
Publisher : Elsevier
ISBN 13 : 0080459498
Total Pages : 551 pages
Book Rating : 4.0/5 (84 download)

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Book Synopsis Handbook of Magnetic Materials by : K.H.J. Buschow

Download or read book Handbook of Magnetic Materials written by K.H.J. Buschow and published by Elsevier. This book was released on 2006-02-08 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 16 of the Handbook on the Properties of Magnetic Materials, as the preceding volumes, has a dual purpose. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 16 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides the readership with novel trends and achievements in magnetism. * composed of topical review articles written by leading authorities.* intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism.* as a work of reference it is intended for scientists active in magnetism research.* provides the readership with novel trends and achievements in magnetism.

Magneto-Thermo-Mechanical Coupling, Stability Analysis and Phenomenological Constitutive Modeling of Magnetic Shape Memory Alloys

Download Magneto-Thermo-Mechanical Coupling, Stability Analysis and Phenomenological Constitutive Modeling of Magnetic Shape Memory Alloys PDF Online Free

Author : Krishnendu Haldar
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (865 download)

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Book Synopsis Magneto-Thermo-Mechanical Coupling, Stability Analysis and Phenomenological Constitutive Modeling of Magnetic Shape Memory Alloys by : Krishnendu Haldar

Download or read book Magneto-Thermo-Mechanical Coupling, Stability Analysis and Phenomenological Constitutive Modeling of Magnetic Shape Memory Alloys written by Krishnendu Haldar and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic shape memory alloys (MSMAs) are a class of active materials that de- form under magnetic and mechanical loading conditions. This work is concerned with the modeling of MSMAs constitutive responses. The hysteretic magneto-mechanical responses of such materials are governed by two major mechanisms which are variant reorientation and field induced phase transformation (FIPT). The most widely used material for variant reorientation is Ni2 MnGa which can produce up to 6% magnetic field induced strain (MFIS) under 5 MPa actuation stress. The major drawback of this material is a low blocking stress, which is overcome in the NiMnCoIn material system through FIPT. This magnetic alloy can exhibit 5% MFIS under 125 MPa actuation stress. The focus of this work is to capture the key magneto-thermo-mechanical responses of such mechanisms through phenomenological modeling. In this work a detailed thermodynamic framework for the electromagnetic interaction within a continuum solid is presented. A Gibbs free energy function is postulated after identifying the external and internal state variables. Material symmetry restrictions are imposed on the Gibbs free energy and on the evolution equations of the internal state variables. Discrete symmetry is considered for single crystals whereas continuous symmetry is considered for polycrystalline materials. The constitutive equations are derived in a thermodynamically consistent way. A specific form of Gibbs free energy for FIPT is proposed and the explicit form of the constitutive equations is derived from the generalized formulation. The model is calibrated from experimental data and different predictions of magneto-thermo-mechanical loading conditions are presented. The generalized constitutive equations are then reduced to capture variant reorientation. A coupled magneto-mechanical boundary value problem (BVP) is solved that accounts for variant reorientation to investigate the influence of the demagnetization effect on the magnetic field and the effect of Maxwell stress on the Cauchy stress. The BVP, which mimics a real experiment, provides a methodology to correlate the difference between the externally measured magnetic data and internal magnetic field of the specimen due to the demagnetization effect. The numerical results show that localization zones appear inside the material between a certain ranges of applied magnetic field. Stability analysis is performed for variant reorientation to analyze these numerical observations. Detailed numerical and analytical analysis is presented to investigate these localization zones. Magnetostatic stability analysis reveals that the MSMA material system becomes unstable when localizations appear due to non-linear magnetization response. Coupled magneto-mechanical stability analysis shows that magnetically induced localization creates stress-localizations in the unstable zones. A parametric study is performed to show the constraints on material parameters for stable and unstable material responses. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148393

Shape-Memory Alloys Handbook

Author : Christian Lexcellent
Publisher : John Wiley & Sons
ISBN 13 : 1118577957
Total Pages : 295 pages
Book Rating : 4.1/5 (185 download)

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Book Synopsis Shape-Memory Alloys Handbook by : Christian Lexcellent

Download or read book Shape-Memory Alloys Handbook written by Christian Lexcellent and published by John Wiley & Sons. This book was released on 2013-04-08 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to understand and describe the martensitic phase transformation and the process of martensite platelet reorientation. These two key elements enable the author to introduce the main features associated with the behavior of shape-memory alloys (SMAs), i.e. the one-way shape-memory effect, pseudo-elasticity, training and recovery. Attention is paid in particular to the thermodynamical frame for solid materials modeling at the macroscopic scale and its applications, as well as to the particular use of such alloys – the simplified calculations for the bending of bars and their torsion. Other chapters are devoted to key topics such as the use of the “crystallographical theory of martensite” for SMA modeling, phenomenological and statistical investigations of SMAs, magneto-thermo-mechanical behavior of magnetic SMAs and the fracture mechanics of SMAs. Case studies are provided on the dimensioning of SMA elements offering the reader an additional useful framework on the subject. Contents 1. Some General Points about SMAs. 2. The World of Shape-memory Alloys. 3. Martensitic Transformation. 4. Thermodynamic Framework for the Modeling of Solid Materials. 5. Use of the “CTM” to Model SMAs. 6. Phenomenological and Statistical Approaches for SMAs. 7. Macroscopic Models with Internal Variables. 8. Design of SMA Elements: Case Studies. 9. Behavior of Magnetic SMAs. 10. Fracture Mechanics of SMAs. 11. General Conclusion. Appendix 1. Intrinsic Properties of Rotation Matrices. Appendix 2. “Twinning Equation” Demonstration. Appendix 3. Calculation of the Parameters a, n and Q from the “Twinning” Equation. Appendix 4. “Twinned” Austenite/Martensite Equation. About the Authors Christian Lexcellent is Emeritus Professor at the École National Supérieure de Mécanique et des Microtechniques de Besançon and a researcher in the Department of Applied Mechanics at FEMTO-ST in France. He is a specialist in the mechanics of materials and phase transition and has taught in the subjects of mechanics of continuum media and shape memory alloys. He is also a member of the International Committee of ESOMAT.

Effects of Magnetic Field on the Shape Memory Behavior of Single and Polycrystalline Magnetic Shape Memory Alloys

Author : Ali Sadi Turabi
Publisher :
ISBN 13 :
Total Pages : 130 pages
Book Rating : 4.:/5 (961 download)

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Book Synopsis Effects of Magnetic Field on the Shape Memory Behavior of Single and Polycrystalline Magnetic Shape Memory Alloys by : Ali Sadi Turabi

Download or read book Effects of Magnetic Field on the Shape Memory Behavior of Single and Polycrystalline Magnetic Shape Memory Alloys written by Ali Sadi Turabi and published by . This book was released on 2015 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Metals Abstracts

Author :
Publisher :
ISBN 13 :
Total Pages : 708 pages
Book Rating : 4.:/5 (319 download)

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Book Synopsis Metals Abstracts by :

Download or read book Metals Abstracts written by and published by . This book was released on 1997 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Magnetic Field-induced Phase Transformation and Power Harvesting Capabilities in Magnetic Shape Memory Alloys

Author : Burak Basaran
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (75 download)

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Book Synopsis Magnetic Field-induced Phase Transformation and Power Harvesting Capabilities in Magnetic Shape Memory Alloys by : Burak Basaran

Download or read book Magnetic Field-induced Phase Transformation and Power Harvesting Capabilities in Magnetic Shape Memory Alloys written by Burak Basaran and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Shape Memory Alloys (MSMAs) combine shape-change/deformation-recovery abilities of heat driven conventional shape memory alloys (SMA) and magnetic field driven magnetostrictives through martensitic transformation. They are promising for actuator applications, and can be employed as sensors/power-harvesters due to their capability to convert mechanical stimuli into magnetic response or vice versa. The purpose of the present work was to investigate magneto-thermo-mechanical (MTM) response of various MSMAs, under simultaneously applied magnetic field, heat and stress. To accomplish this, two novel testing systems which allowed absolute control on magnetic field and stress/strain in a wide and stable range of temperature were designed and manufactured. MTM characterization of MSMAs enabled us to determine the effects of main parameters on reversible magnetic field-induced phase transformation (FIPT), such as magnetocrystalline anisotropy energy, Zeeman energy, stress hysteresis, thermal hysteresis, critical stress to start stress induced phase transformation and crystal orientation. Conventional SMA characteristics of single crystalline Ni2MnGa and NiMnCoIn and polycrystalline NiMnCoAl and NiMnCoSn MSMAs were investigated using the macroscopic MTM testing system to reveal how these conventional properties were linked to magnetic-field-induced actuation. An actuation stress of 5 MPa and a work output of 157 kJm−3 were obtained by the field-induced martensite variant reorientation (VR) in NiMnGa alloys. FIPT was investigated both in Ni2MnGa MSMA and in NiMnCoIn metamagnetic SMA. It proved as an alternative governing mechanism of field-induced shape change to VR in Ni2MnGa single crystals: one-way and reversible (0.5% cyclic magnetic field induced strain (MFIS) under 22 MPa) stress-assisted FIPTs were realized under low field magnitudes (

Smart Materials

Author : Mel Schwartz
Publisher : CRC Press
ISBN 13 : 1420043730
Total Pages : 556 pages
Book Rating : 4.4/5 (2 download)

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Book Synopsis Smart Materials by : Mel Schwartz

Download or read book Smart Materials written by Mel Schwartz and published by CRC Press. This book was released on 2008-11-20 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores State-of-the-Art Work from the World's Foremost Scientists, Engineers, Educators, and Practitioners in the FieldWhy use smart materials?Since most smart materials do not add mass, engineers can endow structures with built-in responses to a myriad of contingencies. In their various forms, these materials can adapt to their environments by c

The Magnetocaloric and Elastocaloric Effects in Magnetic Shape Memory Alloys

Author : Nickolaus Mark Bruno
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (956 download)

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Book Synopsis The Magnetocaloric and Elastocaloric Effects in Magnetic Shape Memory Alloys by : Nickolaus Mark Bruno

Download or read book The Magnetocaloric and Elastocaloric Effects in Magnetic Shape Memory Alloys written by Nickolaus Mark Bruno and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The present work focuses on the microstructural and magneto-thermo-mechanical characterization of off-stoichiometric meta-magnetic shape memory alloys (MMSMAs) with the aim of identifying key material parameters to optimize their giant magneto- (MCE) and elastocaloric (ECE) effects. Several alloy compositions of NiFeGa, Ni(Co)MnIn, and Ni(Co)MnSn have been studied to quantify their solid state energy conversion performance, in particular the conversion of magnetic and mechanical energy into thermal energy, and to reveal how this performance is influenced by microstructural features tailored using carefully selected heat treatments. To identify how heat treatments influence the energy conversion performance of the selected alloys, a previously established thermodynamic framework, which defines the refrigerant capacity (RC) of non-shape memory alloys (SMAs), was employed with the thermodynamic relations describing first order martensitic phase transitions. Applying the RC framework to MMSMAs demonstrated that most of the key materials parameters relating to the martensitic transition can be combined to predict the magnetic field, or mechanical stress, needed to complete the transformation across a specific operating temperature range; reducing these driving force requirements was the primary focus of the experimental part of this work. Magnetometry, calorimetry, and specialized compression tests were performed on the heat treated SMAs. An experimental apparatus, called the magneto-thermo-mechanical characterization (MaTMeCh) device, was designed, constructed, and implemented to reduce the magnetic field requirements needed for a complete field-induced martensitic transformation by simultaneous application of external stress and magnetic field. This device allows simultaneous control of temperature, magnetic field, and stress while measuring magnetization, strain, stress, and temperature. With the MaTMeCh device, uniaxial compressive stresses up to 200MPa, magnetic fields up to 9T, and temperatures between -100°C and 80°C can be applied to a compression specimen. Using the MaTMeCh device, cyclic stress-assisted magnetic field induced transitions demonstrated the full thermal energy conversion capabilities of cost effective meta-magnetic shape memory alloys. Prior to magneto-thermo-mechanical characterization, numerous SMA compositions were fabricated and heat treated to promote grain growth and a specific degree of long range crystallographic order. Studies, herein, indicated that minimizing the microstructural grain constraint, by producing a large grain size to thickness (GS/t) ratio in polycrystalline SMA ribbons, ultimately reduced the magnetic field levels needed to completely harness the SMA's magnetocaloric effect. Additionally, B2 crystallographic ordering in NiCoMnIn single crystals was found to offer a more efficient magnetic to thermal energy conversion efficiency than the typical L21 ordered alloys. Larger caloric effects were measured in the alloys exhibiting a higher martensitic transformation temperature, i.e. the B2 ordered alloys. As such, B2 ordered single crystals were characterized with the MaTMeCh device, thus lending the ability to measure their maximal magnetocaloric performance. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155374

Magneto-mechanical Properties and Applications of Ni-Mn-Ga Ferromagnetic Shape Memory Alloy

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (655 download)

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Book Synopsis Magneto-mechanical Properties and Applications of Ni-Mn-Ga Ferromagnetic Shape Memory Alloy by :

Download or read book Magneto-mechanical Properties and Applications of Ni-Mn-Ga Ferromagnetic Shape Memory Alloy written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: By Steven J. Murray.

The Effect of Crystallographic Orientation and Thermo-mechanical Loading Conditions on the Phase Transformation Characteristics of Ferromagnetic Shape Memory Alloys

Download The Effect of Crystallographic Orientation and Thermo-mechanical Loading Conditions on the Phase Transformation Characteristics of Ferromagnetic Shape Memory Alloys PDF Online Free

Author : Ruixian Zhu
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (74 download)

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Book Synopsis The Effect of Crystallographic Orientation and Thermo-mechanical Loading Conditions on the Phase Transformation Characteristics of Ferromagnetic Shape Memory Alloys by : Ruixian Zhu

Download or read book The Effect of Crystallographic Orientation and Thermo-mechanical Loading Conditions on the Phase Transformation Characteristics of Ferromagnetic Shape Memory Alloys written by Ruixian Zhu and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of crystallographic orientation, temperature and heat treatment on superelastic response of Ni45M36.5Co5In13.5 single crystals were investigated. Superelastic experiments with and without various magnetic field were conducted under compression on a custom built magneto-thermo-mechanical test setup. Magnetostress, which is the difference in critical stress levels for the martensitic transformation with and without magnetic field, was determined as a function of crystallographic orientation, heat treatment and temperature parameters. Magnetostress of [111] crystals was observed to be much higher than that of [001] crystals with same heat treatment. Water quenched samples have the highest magnetostress among other samples with the same orientation that were oil quenched and furnace cooled. Crystal structure and atomic ordering of the samples were examined using Synchrotron High-Energy X-Ray Diffraction to rationalize observed differences. Magnetostress levels were also traced at various temperatures. A Quantum Design superconducting quantum interference device (SQUID) was utilized to examine the magnetic properties of the material. The difference in saturation magnetization at various temperatures was analyzed to explain the temperature effect on magnetostress. Calculations based on the energy conversion from available magnetic energy to mechanical work output were used to predict the magnetic field dependence of magnetostress, which provides a guideline in material selection for the reversible magnetic field induced martensitic phase transformation. Isothermal superelastic response and load-biased shape memory response of Co4Ni33Al29 single crystals were determined as a function of temperature and stress, respectively. The aim of the work is to provide a new direction to understand the anomaly of transformation strain and hysteresis for ferromagnetic shape memory alloys. Thermo-mechanical behavior of Co4Ni33Al29 single crystal was determined by a custom built thermo-mechanical compression setup based on an electromechanical test frame made by MTS. Transformation strain was observed to decrease with increasing applied stress in isothermal tests or increasing temperature in superelastic experiments. The variation in the lattice constant in martensite and austenite was verified to account for such a trend. It was also discovered that both thermal and stress hysteresis decreased with increasing applied stress and temperature, respectively. Multiple factors may be responsible for the phenomenon, including the increase of dislocation, the compatibility between martensite and austenite phase.

Magnetic Shape Memory Alloys with High Actuation Forces

Author :
Publisher :
ISBN 13 :
Total Pages : 52 pages
Book Rating : 4.:/5 (227 download)

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Book Synopsis Magnetic Shape Memory Alloys with High Actuation Forces by :

Download or read book Magnetic Shape Memory Alloys with High Actuation Forces written by and published by . This book was released on 2006 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The specific aims of the project are: 1) Understand governing mechanisms and important physical, mechanical and magnetic parameters responsible for magnetic shape memory phenomena in MSMA alloys in single crystalline form, 2) to develop new nickel, iron or cobalt base ferromagnetic alloy compositions to increase attainable actuation stress levels and to reveal new magneto-thermomechanical mechanisms, 3) to conduct experiments to evaluate whether these compositions will result in good magnetic shape memory response and high actuation force, and 4) to develop a thermodynamically sound model that will predict the coupled effects of mechanical load, magnetic field and temperature on magnetic shape memory behavior.

Discovery, Disruption, and Future Implications of Nanomaterials

Author : Kaur, Hardeep
Publisher : IGI Global
ISBN 13 :
Total Pages : 846 pages
Book Rating : 4.3/5 (693 download)

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Book Synopsis Discovery, Disruption, and Future Implications of Nanomaterials by : Kaur, Hardeep

Download or read book Discovery, Disruption, and Future Implications of Nanomaterials written by Kaur, Hardeep and published by IGI Global. This book was released on 2024-08-29 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complexities of nanotechnology often hamper the discoveries of nanomaterials and their wide range of applications. Researchers face the challenge of keeping up with the rapid development of new materials and figuring out how they can be most efficiently and safely used. As scientists continue to explore the unique properties of nanoparticles, nanofibers, and other nanostructures, there is a growing need for a comprehensive resource to guide them through this intricate landscape. Discovery, Disruption, and Future Implications of Nanomaterials is a book that provides a curated collection of cutting-edge research and insights into the strategic importance of nanomaterials. It bridges the gap between theory and practice, covering fundamental principles to advanced applications in areas such as biomedicine, electronics, energy, and more. The book focuses on carbon-based materials for water treatment, gene/drug delivery, and nanotechnology's role in various fields, equipping readers with the knowledge to navigate the complexities of nanomaterial development and implementation.