Synthesis and Evaluation of Biocompatibility of Cu-Al-Mn Shape Memory Alloy

In recent days, it is being found that shape memory alloys can be used in the medicinal field which helps to alleviate numerous disabilities in people. The Shape memory alloy are evaluated for biocompatibility in present work. The objective is to determine the biocompatibility of Cu-Al-Mn SMAs using the alloy of composition 10-14 weight. % Aluminium (Al), 5-9 weight% Manganese (Mn) and rest copper (Cu) through ingot metallurgy in a constrained atmosphere. The casted samples were homogenisation at 900°C for one and half hours and then rolled at 900°C. The rolled specimens were betatized for half an hour at 900°C followed by Step quenching in boiling water (100°C) and quenching in water at room temperature (30°C). They are cut to the dimension of 10 mm * 10mm * 1mm (breadth*length*height) and then effect of shape memory on obtained alloy was assessed. In continuation, in order to understand the biocompatibility of obtained alloy, the samples were analysed for antibacterial movement by turbido-metric process. The microorganisms utilized for biocompatibility are S.aureus and E.coli. The outcomes showed remarkable biocompatibility with the inference that it can be employed for invitrouses.

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Cold Bending a Ni-Ti Shape Memory Alloy Wire

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.661.98 ◽

2015 ◽

Vol 661 ◽

pp. 98-104 ◽

Cited By ~ 3

Author(s):

Kuang-Jau Fann ◽

Pao Min Huang

Keyword(s):

Shape Memory Alloy ◽

Shape Memory Alloys ◽

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Room Temperature ◽

Aging Treatment ◽

Treatment Temperature ◽

Bending Test ◽

Solution Treatment Temperature

Because of being in possession of shape memory effect and superelasticity, Ni-Ti shape memory alloys have earned more intense gaze on the next generation applications. Conventionally, Ni-Ti shape memory alloys are manufactured by hot forming and constraint aging, which need a capital-intensive investment. To have a cost benefit getting rid of plenty of die sets, this study is aimed to form Ni-Ti shape memory alloys at room temperature and to age them at elevated temperature without any die sets. In this study, starting with solution treatments at various temperatures, which served as annealing process, Ni-rich Ni-Ti shape memory alloy wires were bent by V-shaped punches in different curvatures at room temperature. Subsequently, the wires were aged at different temperatures to have shape memory effect. As a result, springback was found after withdrawing the bending punch and further after the aging treatment as well. A higher solution treatment temperature or a smaller bending radius leads to a smaller springback, while a higher aging treatment temperature made a larger springback. This springback may be compensated by bending the wires in further larger curvatures to keep the shape accuracy as designed. To explore the shape memory effect, a reverse bending test was performed. It shows that all bent wires after aging had a shape recovery rate above 96.3% on average.

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Mechanical Strength Evaluation of a CuAlBe Shape Memory Alloy under Different Thermal Conditions

Materials Science Forum ◽

10.4028/www.scientific.net/msf.643.105 ◽

2010 ◽

Vol 643 ◽

pp. 105-111 ◽

Cited By ~ 5

Author(s):

Danniel Ferreira De Oliveira ◽

Severino Jackson Guedes de Lima ◽

Ieverton Caiandre Andrade Brito ◽

Rodinei Medeiros Gomes ◽

Tadeu Antônio de Avezedo Melo

Keyword(s):

Shape Memory Alloy ◽

Mechanical Strength ◽

Shape Memory Alloys ◽

Shape Memory ◽

Test Temperature ◽

Room Temperature ◽

Thermal Conditions ◽

Protective Atmosphere ◽

Induction Melting ◽

Strength Evaluation

CuAl shape memory alloys containing 0.6wt% and 0.65wt% was casted by induction melting at room temperature without protective atmosphere and their mechanical strength evaluated as a function of the temperature. It was observed that the melting at room temperature does not promote any difficulty to control de beryllium content. The ultimate stress to rupture drop significantly with decreasing the test temperature is such way that the alloys became brittle irrespective to beryllium content.

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Microstructure and Shape Memory Effect of Cu-Al-Be-Mn Quaternary Shape Memory Alloys

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.813-814.213 ◽

2015 ◽

Vol 813-814 ◽

pp. 213-217 ◽

Cited By ~ 3

Author(s):

A.G. Shivasiddaramaiah ◽

Singh Prashant ◽

S.Y. Manjunath ◽

U.S. Mallikarjun

Keyword(s):

High Temperature ◽

Shape Memory Alloys ◽

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Induction Furnace ◽

Beta Phase ◽

Optical Microscope ◽

Ingot Metallurgy ◽

Step Quenching

Copper based shape memory alloys are the alloys prepared with the combination of 66-88 wt% of copper, 10-14 wt% of aluminum, 0.3-0.6 wt% of beryllium and 0.1-0.4 wt% of manganese in the induction furnace through ingot metallurgy. The prepared SMAs is subjected to homogenization, it was observed that the samples exhibits Beta phase at high temperature and shape memory effect after going through step quenching to a low temperature. Microstructure and Shape memory effect was studied with the help of optical microscope and bend test respectively. It was seen that with increase in wt % of manganese the shape memory effect also increases.

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Rigidity of Branching Microstructures in Shape Memory Alloys

Archive for Rational Mechanics and Analysis ◽

10.1007/s00205-021-01679-8 ◽

2021 ◽

Author(s):

Theresa M. Simon

Keyword(s):

Shape Memory Alloy ◽

Shape Memory Alloys ◽

Shape Memory ◽

Differential Inclusion ◽

Linearized Strain ◽

Weak Limits ◽

All Solutions ◽

Rank One ◽

Branched Structures ◽

Habit Planes

AbstractWe analyze generic sequences for which the geometrically linear energy $$\begin{aligned} E_\eta (u,\chi )\,{:}{=} \,\eta ^{-\frac{2}{3}}\int _{B_{1}\left( 0\right) } \left| e(u)- \sum _{i=1}^3 \chi _ie_i\right| ^2 \, \mathrm {d}x+\eta ^\frac{1}{3} \sum _{i=1}^3 |D\chi _i|({B_{1}\left( 0\right) }) \end{aligned}$$ E η ( u , χ ) : = η - 2 3 ∫ B 1 0 e ( u ) - ∑ i = 1 3 χ i e i 2 d x + η 1 3 ∑ i = 1 3 | D χ i | ( B 1 0 ) remains bounded in the limit $$\eta \rightarrow 0$$ η → 0 . Here $$ e(u) \,{:}{=}\,1/2(Du + Du^T)$$ e ( u ) : = 1 / 2 ( D u + D u T ) is the (linearized) strain of the displacement u, the strains $$e_i$$ e i correspond to the martensite strains of a shape memory alloy undergoing cubic-to-tetragonal transformations and the partition into phases is given by $$\chi _i:{B_{1}\left( 0\right) } \rightarrow \{0,1\}$$ χ i : B 1 0 → { 0 , 1 } . In this regime it is known that in addition to simple laminates, branched structures are also possible, which if austenite was present would enable the alloy to form habit planes. In an ansatz-free manner we prove that the alignment of macroscopic interfaces between martensite twins is as predicted by well-known rank-one conditions. Our proof proceeds via the non-convex, non-discrete-valued differential inclusion $$\begin{aligned} e(u) \in \bigcup _{1\le i\ne j\le 3} {\text {conv}} \{e_i,e_j\}, \end{aligned}$$ e ( u ) ∈ ⋃ 1 ≤ i ≠ j ≤ 3 conv { e i , e j } , satisfied by the weak limits of bounded energy sequences and of which we classify all solutions. In particular, there exist no convex integration solutions of the inclusion with complicated geometric structures.

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

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x18812702 ◽

2018 ◽

Vol 30 (3) ◽

pp. 479-494 ◽

Cited By ~ 6

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.

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Crystallographic Attributes of a Shape-Memory Alloy

Journal of Engineering Materials and Technology ◽

10.1115/1.2816005 ◽

1999 ◽

Vol 121 (1) ◽

pp. 93-97 ◽

Cited By ~ 2

Author(s):

Kaushik Bhattacharya

Keyword(s):

Shape Memory Alloy ◽

Shape Memory Alloys ◽

Shape Memory ◽

Nickel Titanium ◽

Potential Applications

Shape-memory Alloys are attractive for many potential applications. In an attempt to provide ideas and guidelines for the development of new shape-memory alloys, this paper reports on a series of investigations that examine the reasons in the crystallography that make (i) shape-memory alloys special amongst martensites and (ii) Nickel-Titanium special among shape-memory alloys.

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Design of Shape Memory Alloy Springs With Applications in Vibration Control

Journal of Vibration and Acoustics ◽

10.1115/1.2930305 ◽

1993 ◽

Vol 115 (1) ◽

pp. 129-135 ◽

Cited By ~ 44

Author(s):

C. Liang ◽

C. A. Rogers

Keyword(s):

Shape Memory Alloy ◽

Shape Memory Alloys ◽

Shape Memory ◽

Vibration Control ◽

Young’S Modulus ◽

Young's Modulus ◽

Design Method ◽

Control Area ◽

Spring Constant ◽

Damping Capacity

Shape memory alloys (SMAs) have several unique characteristics, including their Young’s modulus-temperature relations, shape memory effects, and damping characteristics. The Young’s modulus of the high-temperature austenite of SMAs is about three to four times as large as that of low-temperature martensite. Therefore, a spring made of shape memory alloy can change its spring constant by a factor of three to four. Since a shape memory alloy spring can vary its spring constant, provide recovery stress (shape memory effect), or be designed with a high damping capacity, it may be useful in adaptive vibration control. Some vibration control concepts utilizing the unique characteristics of SMAs will be presented in this paper. Shape memory alloy springs have been used as actuators in many applications although their use in the vibration control area is very recent. Since shape memory alloys differ from conventional alloy materials in many ways, the traditional design approach for springs is not completely suitable for designing SMA springs. Some design approaches based upon linear theory have been proposed for shape memory alloy springs. A more accurate design method for SMA springs based on a new nonlinear thermomechanical constitutive relation of SMA is also presented in this paper.

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Fabrication of an Apatite/Collagen Composite Coating on the NiTi Shape Memory Alloy through Electrochemical Deposition and Coating Characterisation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.618-619.319 ◽

2009 ◽

Vol 618-619 ◽

pp. 319-323 ◽

Cited By ~ 5

Author(s):

Parama Chakraborty Banerjee ◽

Tao Sun ◽

Jonathan H.W. Wong ◽

Min Wang

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Composite Coating ◽

Electrochemical Deposition ◽

Room Temperature ◽

Composite Coatings ◽

Deposition Process ◽

Niti Shape Memory Alloy ◽

X Ray ◽

Niti Sma

To improve the biocompatibility and bioactivity of NiTi shape memory alloy (SMA), apatite/collagen composite coatings were fabricated on the surface of NiTi SMA at room temperature using the electrochemical deposition technique. Spherical apatite particles and fibrous collagen that formed the composite coating were visible under scanning electron microscope (SEM). The Ca/P ratio of the apatite component in the coating, as determined by energy dispersive X-ray spectroscopy (EDX), was about 1.38 which is slightly higher than that of octocalcium phosphate (OCP). X-ray diffraction result showed that the apatite was amorphous, which was due to the low temperature (i.e., room temperature) deposition process. The structure of the composite coatings was further characterized using Fourier transform infrared reflection spectroscopy (FTIR). It was also found that, compared to bare NiTi SMA samples, the wettability of as-deposited samples was increased because of the formation of the composite coating.

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