Fabrication and Characterization of Cu-14Al-3.5Ni Shape Memory Alloys by Ingot Metallurgy

2005 ◽  
Vol 888 ◽  
Author(s):  
K. Jai Ganesh ◽  
Arunya Suresh
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Optical Emission ◽  
Functional Materials ◽  
Cost Effective ◽  
Rolled Strip ◽  
Ingot Metallurgy ◽  
Scanning Calorimetry ◽  
Electric Resistance Furnace

ABSTRACTShape Memory Alloys (SMAs) are versatile functional materials with an I.Q of their own. This class of SMART Materials exhibit unique properties like superelasticity and shape memory effect (SME) which have made them suitable for potential applications. Although Ni-Ti SMAs have attracted attention ever since their inception in 1962, Cu based SMAs due to their ease in fabrication, cost effectiveness and high temperature properties are gaining immense popularity. This research aimed at the fabrication of Cu-14 Al-3.5 Ni (wt %) Shape Memory Alloy by a simple cost effective route and its characterization to correlate its structure and properties. The alloy of desired composition was melted in an Electric Resistance Furnace at 1473 K and cast in a metallic mould. Homogenization was carried out at 1123 K for twenty four hours followed by analysis of chemical composition by Optical Emission Spectroscopy. Transformation temperatures of the alloy were determined using Differential Scanning Calorimetry. Heat treatment operations were carried out at 1273 K for one hour followed by quenching in different media. Optical and SEM micrographs were taken at various magnifications and the formation of self accommodating martensite was observed which was further confirmed by X-Ray Diffraction technique. Further improvements in the mechanical properties of the alloy by quaternary additions of Mn and Ti have been cited. Finally, SME was observed in a rolled strip of the alloy, thus concreting the obtained results.

Experimental Study of Tungsten Inert Gas Pulsed Welding Applied to Ni-Ti Shape Memory Alloy Wires

2015 ◽  
Vol 1765 ◽  
pp. 153-158 ◽  
Author(s):  
Luiz F.A. Rodrigues ◽  
Fernando A. Amorim ◽  
Francisco F.R. Pereira ◽  
Carlos J. de Araújo
Keyword(s):  
Experimental Study ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Welding Process ◽  
Functional Materials ◽  
Inert Gas ◽  
Scanning Calorimetry ◽  
Dissimilar Joints ◽  
Mechanical Cycling

ABSTRACTShape memory alloys are functional materials that can recover plastic strains between 2 and 6%. This property can be used to produce actuators for many areas as medicine, robotic, aeronautic and others. Recently, it has been observed the particular interest for shape memory alloys welding, especially to obtain Ni-Ti similar and dissimilar joints and fabricate simple or complex structures. In this sense, this work present an experimental study of tungsten inert gas pulsed welding applied to Ni-Ti shape memory alloy wires with 0.9 mm in diameter, previously heat treated at 450 °C for 20 minutes and air cooled. For that, it was carried out tensile tests at isothermal temperatures from 40 °C to 90 °C (steps of 10 °C) for welded and unwelded wires. The transformation temperatures obtained from differential scanning calorimetry were compared to verify the effect of welding process. It was also performed a stabilization process by mechanical cycling in some welded and unwelded Ni-Ti wires. The results showed a low strength and strain capacity of the weld joint at higher temperatures. Although, at lowest temperature, close to 40 °C, it was observed higher values of maximum stress and strain for welded Ni-Ti wires.

Batch Fabrication of Shape Memory Actuated Polymer Microvalves by Transfer Bonding Techniques

2009 ◽  
Vol 6 (4) ◽  
pp. 219-227 ◽  
Author(s):  
T. Grund ◽  
C. Megnin ◽  
J. Barth ◽  
M. Kohl
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Life Science ◽  
Functional Materials ◽  
Target System ◽  
Work Output ◽  
Batch Fabrication ◽  
High Work

Polymer based microvalves offer outstanding properties for biomedical and life science applications. They can be produced cost efficiently by batch fabrication methods. Further, by adapting the polymer material, custom-tailored properties of the valve are possible. For mechanically active microvalves, actuation with smart materials like shape memory alloys is highly attractive due to their high work output per volume and favorable scaling behavior. For the integration of such smart materials, fabrication process incompatibilities between the actuator material and the polymer target system need to be avoided. This can be achieved by novel transfer bonding technologies being optimized for batch fabrication. These technologies are demonstrated for polymer microvalves actuated by a shape memory alloy but they can also be applied to other functional materials and structures.

Synthesis and Characterization of Cu-Al-Be-Mn Quaternary Shape Memory Alloys Prepared by Induction Melting Technique

2015 ◽  
Vol 813-814 ◽  
pp. 240-245 ◽  
Author(s):  
A.G. Shivasiddaramaiah ◽  
U.S. Mallikarjun ◽  
S. Prashantha
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Low Cost ◽  
Optical Microscope ◽  
Synthesis And Characterization ◽  
Induction Melting ◽  
Ingot Metallurgy ◽  
Scanning Calorimetry ◽  
Β Phase

Shape memory materials are stimuli-responsive materials. They are widely used in military, medical, safety, and robotics applications. Until recently, only Ni-Ti based SMA’s are commercially used due to its relatively ease of manufacturing. However, the exorbitantly high cost of Ni-Ti based SMA limits its application to niche markets such as medical stents, aerospace and defence. Recently, it is found that Cu based alloys exhibit shape memory behavior. Out of which, Cu-Al-Be-Mn is most interesting SMA in terms of less process complexity and low cost. Cu–Al–Be-Mn shape memory alloys in the range of 09–15 wt.% of aluminium and 0.1-0.4 wt.% of Beryllium and 0.1 to 0.3 wt.% of Manganese, exhibiting β-phase at high temperatures and manifesting shape memory effect upon quenching to lower temperatures, were prepared through ingot metallurgy. The alloy ingots were homogenized followed by step quenching so as to obtain a structure that is completely martensitic. They were subsequently characterized by X-ray diffractogram (XRD), Differential Scanning Calorimetry (DSC) and Optical Microscope (OM). The shape memory properties of the alloys were studied by bend test. This paper emphasizes the synthesis and characterization of the Cu-Al-Be shape memory alloys.

THERMAL PARAMETERS AND STRUCTURAL INVESTIGATIONS OF Cu-BASED SHAPE MEMORY ALLOYS IRRADIATED WITH Co-60

2021 ◽  
Vol 8 (18) ◽  
pp. 151-164
Author(s):  
Şahide Nevin BALO ◽  
Abdulvahap ORHAN
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Thermodynamic Parameters ◽  
Structural Properties ◽  
Functional Materials ◽  
Optical Microscope ◽  
Alloying Elements ◽  
Nuclear Facilities ◽  
Scanning Calorimetry ◽  
Structural Investigations

Gamma radiation is a type of radiation that can change the structural properties of materials. Many physical and structural properties of metals and alloys change due to defects in their crystal structures in response to irradiation. Shape memory alloys (SMAs) are functional materials and are used in mechanical devices for monitoring nuclear facilities. In this study, copper-based SMAs were used. Copper-based SMAs are very sensitive to alloying elements and small changes in element percentages. Cu-11.6Al-0.42Be, Cu-11.8Al-0.47Be, Cu-13Al-4Ni, and Cu-13.5Al-4Ni (wt%) SMA samples were irradiated with a fixed radiation dose of 50 kGy. The effect of irradiation on the thermodynamic parameters and structural properties of copper-based SMAs was investigated. The effects of irradiation on thermodynamic parameters were determined by differential scanning calorimetry (DSC). Structural examinations were made by X-ray diffraction (XRD) and optical microscope observations. Microhardness measurements were taken. The results obtained for Cu-based SMAs were evaluated both as homogeneous and irradiated samples and according to alloying elements.

Intelligent Material Systems: Application of Functional Materials

1998 ◽  
Vol 51 (8) ◽  
pp. 505-521 ◽  
Author(s):  
Junji Tani ◽  
Toshiyuki Takagi ◽  
Jinhao Qiu
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Piezoelectric Materials ◽  
Functional Materials ◽  
Sensors And Actuators ◽  
Magnetostrictive Materials ◽  
Material Systems ◽  
Intelligent Material ◽  
Magneto Rheological

This article presents a review of recent important developments in the field of intelligent material systems. Intelligent material systems, sometimes referred to as smart materials, can adjust their behavior to changes of external or internal parameters analogously to biological systems. In these systems, sensors, actuators and controllers are seamlessly integrated with structural materials at the macroscopic or mesoscopic level. In general, sensors and actuators are made of functional materials and fluids such as piezoelectric materials, magnetostrictive materials, shape memory alloys, polymer hydrogels, electro- and magneto-rheological fluids and so on. This article is specifically focused on the application of piezoelectric materials, magnetostrictive materials and shape memory alloys to intelligent material systems used to control the deformation, vibration and fracture of composite materials and structures. This review article contains 188 references.

Effects of Annealing on Microstructure and Martensitic Transition of Ni-Mn-Co-In Ferromagnetic Shape Memory Alloys

2011 ◽  
Vol 674 ◽  
pp. 171-175
Author(s):  
Katarzyna Bałdys ◽  
Grzegorz Dercz ◽  
Łukasz Madej
Keyword(s):  
Electron Microscopy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Martensitic Transition ◽  
Magnetic Shape Memory ◽  
Ferromagnetic Shape Memory Alloys ◽  
Initial State ◽  
X Ray ◽  
Ferromagnetic Shape Memory

The ferromagnetic shape memory alloys (FSMA) are relatively the brand new smart materials group. The most interesting issue connected with FSMA is magnetic shape memory, which gives a possibility to achieve relatively high strain (over 8%) caused by magnetic field. In this paper the effect of annealing on the microstructure and martensitic transition on Ni-Mn-Co-In ferromagnetic shape memory alloy has been studied. The alloy was prepared by melting of 99,98% pure Ni, 99,98% pure Mn, 99,98% pure Co, 99,99% pure In. The chemical composition, its homogeneity and the alloy microstructure were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phase composition was also studied by X-ray analysis. The transformation course and characteristic temperatures were determined by the use of differential scanning calorimetry (DSC) and magnetic balance techniques. The results show that Tc of the annealed sample was found to decrease with increasing the annealing temperature. The Ms and Af increases with increasing annealing temperatures and showed best results in 1173K. The studied alloy exhibits a martensitic transformation from a L21 austenite to a martensite phase with a 7-layer (14M) and 5-layer (10M) modulated structure. The lattice constants of the L21 (a0) structure determined by TEM and X-ray analysis in this alloy were a0=0,4866. The TEM observation exhibit that the studied alloy in initial state has bigger accumulations of 10M and 14M structures as opposed from the annealed state.

Adaptive Elastic SMA Elements for Damping Applications

2013 ◽  
Author(s):  
Alexander Czechowicz ◽  
Peter Dültgen ◽  
Sven Langbein
Keyword(s):  
Boundary Conditions ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Electrical Resistance ◽  
Thermal Activation ◽  
Hysteretic Behavior ◽  
Damping Function ◽  
Actual Shape ◽  
Elastic Elements

Shape memory alloys (SMA) are smart materials, which have two technical usable effects: While pseudoplastic SMA have the ability to change into a previously imprinted actual shape through the means of thermal activation, pseudoelastic SMA show a reversible mechanical elongation up to 8% at constant temperature. The transformation between the two possible material phases (austenite and martensite) shows a hysteretic behavior. As a result of these properties, SMA can be used as elastic elements with intrinsic damping function. Additionally the electrical resistance changes remarkably during the material deformation. These effects are presented in the publication in combination with potential for applications in different branches at varying boundary conditions. The focus of the presented research is concentrated on the application of elastic elements with adaptive damping function. As a proof for the potential considerations, an application example sums up this presentation.

Modeling Smart Materials Using Hysteretic Recurrent Neural Networks

2009 ◽  
Author(s):  
Arun Veeramani ◽  
John Crews ◽  
Gregory D. Buckner
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Real Time Control ◽  
Ferromagnetic Shape Memory Alloys ◽  
Two Phase ◽  
Time Control ◽  
Novel Approach ◽  
Three Phase ◽  
Ferromagnetic Shape Memory

This paper describes a novel approach to modeling hysteresis using a Hysteretic Recurrent Neural Network (HRNN). The HRNN utilizes weighted recurrent neurons, each composed of conjoined sigmoid activation functions to capture the directional dependencies typical of hysteretic smart materials (piezoelectrics, ferromagnetic, shape memory alloys, etc.) Network weights are included on the output layer to facilitate training and provide statistical model information such as phase fraction probabilities. This paper demonstrates HRNN-based modeling of two- and three-phase transformations in hysteretic materials (shape memory alloys) with experimental validation. A two-phase network is constructed to model the displacement characteristics of a shape memory alloy (SMA) wire under constant stress. To capture the more general thermo-mechanical behavior of SMAs, a three-phase HRNN model (which accounts for detwinned Martensite, twinned Martensite, and Austensite phases) is developed and experimentally validated. The HRNN modeling approach described in this paper readily lends itself to other hysteretic materials and may be used for developing real-time control algorithms.

Shape memory alloy–actuated prestressed composites with application to morphing automotive fender skirts

2018 ◽  
Vol 30 (3) ◽  
pp. 479-494 ◽  
Author(s):  
Venkata Siva C Chillara ◽  
Leon M Headings ◽  
Ryohei Tsuruta ◽  
Eiji Itakura ◽  
Umesh Gandhi ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Design Procedure ◽  
Building Blocks ◽  
Smart Composite ◽  
Thermally Induced ◽  
One Dimensional ◽  
Flat Shape

This work presents smart laminated composites that enable morphing vehicle structures. Morphing panels can be effective for drag reduction, for example, adaptive fender skirts. Mechanical prestress provides tailored curvature in composites without the drawbacks of thermally induced residual stress. When driven by smart materials such as shape memory alloys, mechanically-prestressed composites can serve as building blocks for morphing structures. An analytical energy-based model is presented to calculate the curved shape of a composite as a function of force applied by an embedded actuator. Shape transition is modeled by providing the actuation force as an input to a one-dimensional thermomechanical constitutive model of a shape memory alloy wire. A design procedure, based on the analytical model, is presented for morphing fender skirts comprising radially configured smart composite elements. A half-scale fender skirt for a compact passenger car is designed, fabricated, and tested. The demonstrator has a domed unactuated shape and morphs to a flat shape when actuated using shape memory alloys. Rapid actuation is demonstrated by coupling shape memory alloys with integrated quick-release latches; the latches reduce actuation time by 95%. The demonstrator is 62% lighter than an equivalent dome-shaped steel fender skirt.

Smart materials: Properties, design and mechatronic applications

2016 ◽  
Vol 233 (4) ◽  
pp. 734-762 ◽  
Author(s):  
A Spaggiari ◽  
D Castagnetti ◽  
N Golinelli ◽  
E Dragoni ◽  
G Scirè Mammano
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Piezoelectric Materials ◽  
Magnetorheological Fluids ◽  
Research Perspective ◽  
Active Devices ◽  
Complete Survey ◽  
Basic Equations ◽  
Commercial Applications

This paper describes the properties and the engineering applications of the smart materials, especially in the mechatronics field. Even though there are several smart materials which all are very interesting from the research perspective, we decide to focus the work on just three of them. The adopted criterion privileges the most promising technologies in terms of commercial applications available on the market, namely: magnetorheological fluids, shape memory alloys and piezoelectric materials. Many semi-active devices such as dampers or brakes or clutches, based on magnetorheological fluids are commercially available; in addition, we can trace several applications of piezo actuators and shape memory-based devices, especially in the field of micro actuations. The work describes the physics behind these three materials and it gives some basic equations to dimension a system based on one of these technologies. The work helps the designer in a first feasibility study for the applications of one of these smart materials inside an industrial context. Moreover, the paper shows a complete survey of the applications of magnetorheological fluids, piezoelectric devices and shape memory alloys that have hit the market, considering industrial, biomedical, civil and automotive field.

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