Download or read book Thin Films of Ferromagnetic Shape Memory Alloys written by Iván Rodríguez Aseguinolaza and published by . This book was released on 2014 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ferromagnetic Shape Memory Alloys II written by Volodymyr A. Chernenko and published by Trans Tech Publications Ltd. This book was released on 2009-12-03 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters CPCI-S (WoS). This work on Ferromagnetic Shape Memory Alloys contains selected peer-reviewed papers. Such materials belong to the most exciting and fastest-growing group of martensitic multifunctional materials. The selected papers cover the following topics of: Basic phenomena and theory; Structure and magnetic properties; Magnetomechanics and magnetocaloric effect; Thin films and composites; Modeling and simulations and Processing and engineering.

Download or read book Thin Film Shape Memory Alloys written by Shuichi Miyazaki and published by Cambridge University Press. This book was released on 2009-09-03 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, the first dedicated to this exciting and rapidly growing field, enables readers to understand and prepare high-quality, high-performance TiNi shape memory alloys (SMAs). It covers the properties, preparation and characterization of TiNi SMAs, with particular focus on the latest technologies and applications in MEMS and biological devices. Basic techniques and theory are covered to introduce new-comers to the subject, whilst various sub-topics, such as film deposition, characterization, post treatment, and applying thin films to practical situations, appeal to more informed readers. Each chapter is written by expert authors, providing an overview of each topic and summarizing all the latest developments, making this an ideal reference for practitioners and researchers alike.

Download or read book Microstructure of Epitaxial Thin Films of the Ferromagnetic Shape Memory Alloy Ni 1tn2MnGa written by Tobias Eichhorn and published by . This book was released on 2011 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microstructure of Epitaxial Thin Films of the Ferromagnetic Shape Memory Alloy Ni 2 MnGa written by Tobias Eichhorn and published by . This book was released on 2011 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phase field Modeling of Multi domain Evolution in Ferromagnetic Shape Memory Alloys and of Polycrystalline Thin Film Growth written by Christian Mennerich and published by KIT Scientific Publishing. This book was released on 2014-05-13 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: The phase-field method is a powerful tool in computer-aided materials science as it allows for the analysis of the time-spatial evolution of microstructures on the mesoscale. A multi-phase-field model is adopted to run numerical simulations in two different areas of scientific interest: Polycrystalline thin films growth and the ferromagnetic shape memory effect. FFT-techniques, norm conservative integration and RVE-methods are necessary to make the coupled problems numerically feasible.

Download or read book Synthesis and Characterization of NiMnGa Ferromagnetic Shape Memory Alloy Thin Films written by Nishitha Jetta and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ni-Mn-Ga is a ferromagnetic shape memory alloy that can be used for future sensors and actuators. It has been shown that magnetic field can induce phase transformation and consequently large strain in stoichiometric Ni2MnGa. Since then considerable progress has been made in understanding the underlying science of shape memory and ferromagnetic shape memory in bulk materials. Ni-Mn-Ga thin films, however is a relatively under explored area. Ferromagnetic shape memory alloy thin films are conceived as the future MEMS sensor and actuator materials. With a 9.5 percent strain rate reported from magnetic reorientation, Ni-Mn-Ga thin films hold great promise as actuator materials. Thin films come with a number of advantages and challenges as compared to their bulk counterparts. While properties like mechanical strength, uniformity are much better in thin film form, high stress and constraint from the substrate pose a significant challenge for reorientation and shape memory behavior. In either case, it is very important to understand their behavior and examine their properties. This thesis is an effort to contribute to the literature of Ni-Mn-Ga thin films as ferromagnetic shape memory alloys. The focus of this project is to develop a recipe for fabricating NiMnGa thin films with desired composition and microstructure and hence unique properties for future MEMS actuator materials and characterize their properties to aid better understanding of their behavior. In this project NiMnGa thin films have been fabricated using magnetron sputtering on a variety of substrates. Magnetron sputtering technique allows us to tailor the composition of films which is crucial for controlling the phase transformation properties of NiMnGa films. The composition is tailored by varying several deposition parameters. Microstructure of the films has been investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. Mechanical properties of as-deposited films have been probed using nano-indentation technique. The chemistry of sputtered films is determined quantitatively by wavelength dispersive X-ray spectroscopy (WDS). Phase transformation is studied by using a combination of differential scanning calorimetry (DSC), in-situ heating in TEM and in-situ XRD instruments. Magnetic properties of films are examined using superconducting quantum interface device (SQUID).

Download or read book An Analysis of Ferromagnetic Shape Memory Alloys Produced by Melt Spinning Sputtering and Pulsed Laser Deposition written by Neil Dearing and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferromagnetic shape memory alloys (FSMA) have recently attracted much interest and research because of their large magnetic-field induced strain. Strains of up to 10% have been reported in single crystals of Ni2MnGa at room temperature. The mechanism of twin boundary motion is understood to be responsible for the strain in FSMA?s and theoretically allows for a full crystal lattice distortion strain, which is 10% in the case of orthorhombic martensites and 5-6% in the case of tetragonal martensites. These strains however are only achievable in single crystals and much smaller strains have been observed in polycrystalline samples. Here, competition of the randomly orientated grains restrict the cooperative twin boundary motion that is evident in single crystals. Melt spun ribbons are often highly textured and may offer a method of producing ribbons in a form useful as a start material for applications, i.e. basis of a useful?bulk? compact form. Magnetic and structural properties of melt spun Ni-Mn-Ga have previously been reported. Applied magnetic field has been shown to affect the transformation strain on cooling. Ni-Mn-Ga alloys form a Heusler (L21) lattice which, on cooling, undergoes a diffusionless transformation beginning at the martensite start temperature Ms into either a tetragonal or orthorhombic martensite, both of which are highly twinned. The reverse transformation begins at the austenite start temperature As and both transformations occur over a range of approximately 10K. The type of martensite formed depends strongly on the composition of the sample and its thermal history. The influence of atomic order in Ni-Mn-Ga alloys has also been studied. It has been found that the degree of atomic order plays a large part in determining the martensitic transition temperature. This temperature is suppressed significantly in the disordered B2 structure where there is little correlation of the Mn and Ga atoms at the body center. Ni2MnGa undergoes a B2 to L21 (Heusler) transition at 1071K on cooling. In this work the structural and magnetic properties of melt spun Ni-Mn-Ga ribbons are presented and the effect of an applied magnetic field on the transformation strain is shown for the case of annealed ribbons under tensile stress. It is the intention of this work to explore the properties of melt-spun ribbons of the ferromagnetic shape memory alloys Ni-Mn-Ga and Ni-Fe-Ga with the addition of Tb. A range of compositions of both alloys have been created and analysed for both structural and magnetic properties. Melt spun ribbons are usually either amorphous or nanocrystalline, so the effect of heat treatments to both relieve stress and re-crystallise the ribbons is also explored. This provides some insight into how the crystal structure and magnetic properties evolve with annealing temperature. Thin films of these ferromagnetic shape memory alloys were also produced by both sputtering and pulsed laser deposition in order to characterise their behaviour and gain some insight into the growth conditions necessary to successfully produce thin films of ferromagnetic shape memory alloys. This was done because thin films grown at low temperatures can have similar properties to the melt spun ribbons, in that they are nanocrystalline or amorphous. It was hoped that producing and analysing these thin films would yield some more information about the behaviour of polycrystalline ferromagnetic shape memory alloys.

Download or read book Thin Film Shape Memory Alloys written by Shuichi Miyazaki and published by Cambridge University Press. This book was released on 2009-09-03 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first dedicated book describing the properties, preparation, characterization and device applications of TiNi-based shape memory alloys.

Download or read book Fabrication and Crystallographic Features of Epitaxial NiMnGa Ferromagnetic Shape Memory Alloy Thin Films written by Bo Yang and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Epitaxial Ni-Mn-Ga thin films have attracted considerable attention, since they are promising candidates for magnetic sensors and actuators in micro-electro-mechanical systems. Comprehensive information on the microstructural and crystallographic features of the NiMnGa films and their relationship with the constraints of the substrate is essential for further property optimization. In the present work, epitaxial Ni-Mn-Ga thin films were produced by DC magnetron sputtering and then characterized by x-ray diffraction technique (XRD) and backscatter electron diffraction equipped in scanning electron microscope (SEM-EBSD). Epitaxial NiMnGa thin films with nominal composition of Ni50Mn30Ga20 and thickness of 1.5 μm were successfully fabricated on MgO monocrystalline substrate by DC magnetron sputtering, after the optimization of sputtering parameters such as sputtering power, substrate temperature and seed layer by the present work. XRD diffraction measurements demonstrate that the epitaxial NiMnGa thin films are composed of three phases: austenite, NM martensite and 7M martensite. With the optimized measurement geometries, maximum number of diffraction peaks of the concerning phases, especially of the low symmetrical 7M martensite, are acquired and analyzed. The lattice constants of all the three phases under the constraints of the substrate in the films are fully determined. These serve as prerequisites for the subsequent EBSD crystallographic orientation characterizations. SEM-EBSD in film depth analyses further verified the co-existence situation of the three constituent phases: austenite, 7M martensite and NM martensite. NM martensite is located near the free surface of the film, austenite above the substrate surface, and 7M martensite in the intermediate layers between austenite and NM martensite. Microstructure characterization shows that both the 7M martensite and NM martensite are of plate morphology and organized into two characteristic zones featured with low and high relative second electron image contrast. Local martensite plates with similar plate morphology orientation are organized into plate groups or groups or variant colonies. Further EBSD characterization indicates that there are four distinct martensite plates in each variant groups for both NM and 7M martensite. Each NM martensite plate is composed of paired major and minor lamellar variants in terms of their thicknesses having a coherent interlamellar interface, whereas, each 7M martensite plate contains one orientation variant. Thus, there are four orientation 7M martensite variants and eight orientation NM martensite variants in one variant group. According to the crystallographic orientation of martensites and the crystallographic calculation, for NM martensite, the inter-plate interfaces are composed of compound twins in adjacent NM plates. The symmetrically distribution of compound twins results in the long and straight plate interfaces in the low relative contrast zone. The asymmetrically distribution leads to the change of inter-plate interface orientation in the high relative contrast zone. For 7M martensite, both Type-I and Type-II twin interfaces are nearly perpendicular to the substrate surface in the low relative contrast zones. The Type-I twin pairs appear with much higher frequency, as compared with that of the Type-II twin pairs. However, there are two Type-II twin interface trace orientations and one Type-I twin interface trace orientation in the high relative contrast zones. The Type-II twin pairs are more frequent than the Type-I twin pairs. The inconsistent occurrences of the different types of twins in different zones are originated from the substrate constrain. The crystallographic calculation also indicates that the martensitic transformation sequence is from Austenite to 7M martensite and then transform into NM martensite (A→7M→NM). [...].

Download or read book Phase field Modeling of Multi domain Evolution in Ferromagnetic Shape Memory Alloys and of Polycrystalline Thin Film Growth written by Christian Mennerich and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Ferromagnetic Shape Memory Thin Film written by Tianyu Zhang and published by . This book was released on 2006 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Molecular Beam Epitaxial Growth and Phase Transformation Behaviors of Heusler type Single Crystal Ferromagnetic Shape Memory Thin Films written by Chung-Ping Shih and published by . This book was released on 2005 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shape Memory Alloys 2017 written by Takuo Sakon and published by MDPI. This book was released on 2018-03-15 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue Shape Memory Alloys 2017" that was published in Metals

Download or read book Advances in Shape Memory Materials written by Qingping Sun and published by Springer. This book was released on 2017-03-14 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to the development of the shape memory materials and their applications. It covers many aspects of smart materials. It also describes the method on how we can obtain not only large recovery strains but also high recovery stress, energy storage and energy dissipation in applications. This volume treats the mechanical properties of shape memory alloys, shape memory polymers and the constitutive equations of the materials which are necessary to design the shape memory elements in applications. It also deals with the fatigue properties of materials, the method to design the shape memory elements, and the shape memory composites. The authors are international experts on shape memory alloys and shape memory polymers in the metallurgical, chemical, mechanical and engineering fields. The book will be of interest to graduate students, engineers, scientists and designers who are working in the field of electric and mechanical engineering, industries, medical engineering, aerospace engineering, robots, automatic machines, clothes and recycling for research, design and manufacturing.

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.