Shape Memory Alloys

Shape Memory Alloy Engineering introduces materials, mechanical, and aerospace engineers to shape memory alloys (SMAs), providing a unique perspective that combines fundamental theory with new approaches to design and modeling of actual SMAs as compact and inexpensive actuators for use in aerospace and other applications. With this book readers will gain an understanding of the intrinsic properties of SMAs and their characteristic state diagrams, allowing them to design innovative compact actuation systems for applications from aerospace and aeronautics to ships, cars, and trucks. The book realistically discusses both the potential of these fascinating materials as well as their limitations in everyday life, and how to overcome some of those limitations in order to achieve proper design of useful SMA mechanisms. Discusses material characterization processes and results for a number of newer SMAs Incorporates numerical (FE) simulation and integration procedures into commercial codes (Msc/Nastran, Abaqus, and others) Provides detailed examples on design procedures and optimization of SMA-based actuation systems for real cases, from specs to verification lab tests on physical demonstrators One of the few SMA books to include design and set-up of demonstrator characterization tests and correlation with numerical models

This book provides a working knowledge of the modeling and engineering applications of shape memory alloys (SMAs), beginning with a rigorous introduction to continuum mechanics and continuum thermodynamics as they relate to the development of SMA modeling.Modern SMAs can recover from large amounts of bending and deformation, and millions of repetitions within recoverable ranges. SMAs are used in the medical industry to create stents, in the dental industry to create dental and orthodontic archwires, and in the aerospace industry to create fluid fittings. The text presents a unified approach to the constitutive modeling of SMAs, including modeling of magnetic and high temperature SMAs.

Engineering Aspects of Shape Memory Alloys provides an understanding of shape memory by defining terms, properties, and applications. It includes tutorials, overviews, and specific design examples—all written with the intention of minimizing the science and maximizing the engineering aspects. Although the individual chapters have been written by many different authors, each one of the best in their fields, the overall tone and intent of the book is not that of a proceedings, but that of a textbook. The book consists of five parts. Part I deals with the mechanism of shape memory and the alloys that exhibit the effect. It also defines many essential terms that will be used in later parts. Part II deals primarily with constrained recovery, but to some extent with free recovery. There is an introductory paper which defines terms and principles, then several specific examples of products based on constrained recovery. Both Parts III and IV deal with actuators. Part III introduces engineering principles while Part IV presents several of the specific examples. Finally, Part V deals with superelasticity, with an introductory paper and then several specific examples of product engineering.

A shape memory alloy (SMA, also known as a smart metal, memory alloy, or muscle wire) is an alloy that "remembers" its shape, and can be returned to that shape after being deformed, by applying heat to the alloy. When the shape memory effect is correctly harnessed, this material becomes a lightweight, solid-state alternative to conventional actuators such as hydraulic, pneumatic, and motor-based systems. Shape memory alloys have numerous applications in the medical and aerospace industries. This book presents the latest research in the field from around the globe.

Pseudoelasticity of Shape Memory Alloys: Theory and Experimental Studies is devoted to the phenomenon of pseudoelasticity (superelasticity) exhibited by shape memory alloy materials. It provides extensive introductory content on the state-of-the-art in the field, including SMA materials development, definition of shape memory effects, and discussions on where shape memory behavior is found in various engineering application areas. The book features a survey of modeling approaches targeted at reliable prediction of SMA materials’ behavior on different scales of observation, including atomistic, microscopic, mezoscopic, and macroscopic. Researchers and graduate students will find detailed information on the modern methodologies used in the process of building constitutive models of advanced materials exhibiting complex behavior. Introduces the phenomenon of pseudoelasticity exhibited by shape memory alloy materials Features a survey of modeling approaches targeted at reliable prediction of SMN materials' behavior on different scales of observation Provides extensive coverage of the state-of-the-art in the field Ideal reference for researchers and graduate students interested in the modern methodologies used in the process of building constitutive models of advanced materials

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.

Shape memory and superelastic alloys possess properties not present in ordinary metals meaning that they can be used for a variety of applications. Shape memory and superelastic alloys: Applications and technologies explores these applications discussing their key features and commercial performance. Readers will gain invaluable information and insight into the current and potential future applications of shape memory alloys. Part one covers the properties and processing of shape memory effect and superelasticity in alloys for practical users with chapters covering the basic characteristics of Ti-Ni-based and Ti-Nb-based shape memory and superelastic (SM/SE) alloys, the development and commercialisation of TiNi and Cu-based alloys, industrial processing and device elements, design of SMA coil springs for actuators before a final overview on the development of SM and SE applications. Part two introduces SMA application technologies with chapters investigating SMAs in electrical applications, hot-water supply, construction and housing, automobiles and railways and aerospace engineering before looking at the properties, processing and applications of Ferrous (Fe)-based SMAs. Part three focuses on the applications of superelastic alloys and explores their functions in the medical, telecommunications, clothing, sports and leisure industries. The appendix briefly describes the history and activity of the Association of Shape Memory Alloys (ASMA). With its distinguished editors and team of expert contributors, Shape memory and superelastic alloys: Applications and technologies is be a valuable reference tool for metallurgists as well as for designers, engineers and students involved in one of the many industries in which shape memory effect and superelasticity are used such as construction, automotive, medical, aerospace, telecommunications, water/heating, clothing, sports and leisure. Explores important applications of shape memory and superelastic alloys discussing their key features and commercial performance Assesses the properties and processing of shape memory effect and superelasticity in alloys for practical users with chapters covering the basic characteristics Introduces SMA application technologies investigating SMAs in electrical applications, hot-water supply, construction and housing, automobiles and railways and aerospace engineering

This book showcases different processes of fabrication and processing applied to shape memory alloys. It provides details and collective information on working principles, process mechanisms, salient features, novel aspects, process capabilities, properties of material and unique applications of shape memory alloys. The recent progress on fabrication and processing are specially addressed in this book. It covers major topics of manufacturing such as machining, joining, welding and processing of shape memory alloys.