Early Mobilization Using Heat Treated Shape Memory Alloy (SMA) for Rehabilitation Phases

2016 ◽  
Vol 724 ◽  
pp. 112-116 ◽  
Author(s):  
Ahmad Majdi Abdul-Rani ◽  
Subramaniam Krishnan ◽  
T. Nagarajan ◽  
T.V.V.L.N. Rao ◽  
Ramanathan Ramiah ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Manufacturing Industry ◽  
Medical Engineering ◽  
Early Mobilization ◽  
Original Position ◽  
Foot Diseases ◽  
Heat Treated ◽  
Mechanical Procedure ◽  
Effective Use

Shape Memory Alloy (SMA) is a material with the ability to return to its original position, when being subjected to an appropriate thermo mechanical procedure. SMA find very wide applications in various facets of robotic and bio medical engineering. In this paper, review on ankle/foot diseases and the effective use of heat treated SMA was carried out. The manufacturing industry normally uses a range of between 200°C to 400°C to shape any biomedical product which has been used as the benchmark temperature throughout this research. The results suggested that annealing of 200°C produced the best suited for generating substantial displacement which can promote early rehabilitation of ankle/foot.

Sub-Structure Pseudo-Dynamic Response Test of a Pseudo-Elastic Bracing System Made of Shape Memory Alloy

2005 ◽  
Vol 297-300 ◽  
pp. 628-634 ◽  
Author(s):  
Kenichi Ohi ◽  
Jae Hyouk Choi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Original Position ◽  
Small Displacement ◽  
Structural System ◽  
Dynamic Tests ◽  
System A ◽  
Hysteretic Damper ◽  
Bracing System ◽  
Fail Safe

This paper deals with shape memory alloy. As a first step to assess the applicability of this kind of alloy in a structural system, a tension bar made of this kind of alloy that exhibits pseudo-elasticity at room temperature is used herein as a passive bracing system. This paper describes sub-structure pseudo-dynamic tests on pseudo-elastic bracing system with hysteretic damper. A pseudo-elastic bracing system is better to be used with other hysteretic elements such as a hysteretic damper. A damper provides energy dissipation within small displacement levels, and a pseudo-elastic bracing system works in turn as a back-up/fail-safe system when an accidental failure of damper or damper interface occurs, and also it helps to pull back the structure to the original position by uninstalling the damper after earthquake.

scholarly journals Effect of Heat Treatment Temperature on Martensitic Transformation and Superelasticity of the Ti49Ni51 Shape Memory Alloy

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2539 ◽  
Author(s):  
Peiyou Li ◽  
Yongshan Wang ◽  
Fanying Meng ◽  
Le Cao ◽  
Zhirong He
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Thermal Hysteresis ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Different Temperatures ◽  
Tini Phase ◽  
Rapidly Solidified

The martensitic transformation and superelasticity of Ti49Ni51 shape memory alloy heat-treatment at different temperatures were investigated. The experimental results show that the microstructures of as-cast and heat-treated (723 K) Ni-rich Ti49Ni51 samples prepared by rapidly-solidified technology are composed of B2 TiNi phase, and Ti3Ni4 and Ti2Ni phases; the microstructures of heat-treated Ti49Ni51 samples at 773 and 823 K are composed of B2 TiNi phase, and of B2 TiNi and Ti2Ni phases, respectively. The martensitic transformation of as-cast Ti49Ni51 alloy is three-stage, A→R→M1 and R→M2 transformation during cooling, and two-stage, M→R→A transformation during heating. The transformations of the heat-treated Ti49Ni51 samples at 723 and 823 K are the A↔R↔M/A↔M transformation during cooling/heating, respectively. For the heat-treated alloy at 773 K, the transformations are the A→R/M→R→A during cooling/heating, respectively. For the heat-treated alloy at 773 K, only a small thermal hysteresis is suitable for sensor devices. The stable σmax values of 723 and 773 K heat-treated samples with a large Wd value exhibit high safety in application. The 773 and 823 K heat-treated samples have large stable strain–energy densities, and are a good superelastic alloy. The experimental data obtained provide a valuable reference for the industrial application of rapidly-solidified casting and heat-treated Ti49Ni51 alloy.

scholarly journals Fabrication and Two-Way Deformation of Shape Memory Composite with SMA and SMP

2010 ◽  
Vol 638-642 ◽  
pp. 2189-2194 ◽  
Author(s):  
Hisaaki Tobushi ◽  
Shunichi Hayashi ◽  
Y. Sugimoto ◽  
K. Date
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Memory Polymer ◽  
Bending Deformation ◽  
Heating And Cooling ◽  
Round Shape ◽  
Heat Treated ◽  
Shape Memory Composite

The shape memory composite (SMC) with shape memory alloy (SMA) and shape memory polymer (SMP) was fabricated, and the two-way bending deformation and recovery force were investigated. The results obtained can be summarized as follows. (1) Two kinds of SMA tapes which show the shape memory effect and superelasticity were heat-treated to memorize the round shape, respectively. The shape-memorized round SMA tapes were sandwiched between the SMP sheets, and the SMC belt was fabricated. (2) The two-way bending deformation with an angle of 56 degrees is observed during heating and cooling. (3) If the SMC belt is heated and cooled by keeping the form, recovery force increases during heating and decreases during cooling.

Behavio of Supeaplastically Extruded Cu-26wt%Zn–3.5wt%Al Shape Memory Alloy

1990 ◽  
Vol 196 ◽  
Author(s):  
Zheng Zhengyt ◽  
Zhcng Weijian ◽  
Lin Fuzeng ◽  
Chew Yingsheng
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Strain Rate ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Heat Treated

ABSTRACTThe influence of superplastic extrusion on the microstructures and the shape memory effect of the Cu-Zn-Al shape memory alloys has been investigated. The shape memory alloy Cu-26%wt%Zn-3.5wt%Al is superplastio with an index of strain rate sensitivity n = 0.48 at 600°C, at a strain of . After extrusion under the superplastio condition the miorostruotures are improved and no cavities are observed. The superplastically extruded specimens of this alloy were heat-treated to obtain the shape memory effect. These specimens indicate that no deterioration of shape memory effect of the alloy is induced by the superplastio extrusion and the shape memory effect of the alloy is somewhat improved.

scholarly journals Microstructure and Mechanical Properties of NiTi-Based Eutectic Shape Memory Alloy Produced via Selective Laser Melting In-Situ Alloying by Nb

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2696
Author(s):  
Igor Polozov ◽  
Anatoly Popovich
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Selective Laser Melting ◽  
Mechanical Tests ◽  
Laser Melting ◽  
Heat Treated ◽  
Powder Particles ◽  
Martensitic Phase Transformations ◽  
Nb Addition

This paper presents the results of selective laser melting (SLM) process of a nitinol-based NiTiNb shape memory alloy. The eutectic alloy Ni45Ti45Nb10 with a shape memory effect was obtained by SLM in-situ alloying using a powder mixture of NiTi and Nb powder particles. Samples with a high relative density (>99%) were obtained using optimized process parameters. Microstructure, phase composition, tensile properties, as well as martensitic phase transformations temperatures of the produced alloy were investigated in as-fabricated and heat-treated conditions. The NiTiNb alloy fabricated using the SLM in-situ alloying featured the microstructure consisting of the NiTi matrix, fine NiTi+β-Nb eutectics, as well as residual unmelted Nb particles. The mechanical tests showed that the obtained alloy has a yield strength up to 436 MPa and the tensile strength up to 706 MPa. At the same time, in-situ alloying with Nb allowed increasing the hysteresis of martensitic transformation as compared to the alloy without Nb addition from 22 to 50 °C with an increase in Af temperature from −5 to 22 °C.

Orientation Dependent Internal Friction of Textured Ti-Nb-Al Shape Memory Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 1533-1536 ◽  
Author(s):  
Y. Yamamoto ◽  
Tomonari Inamura ◽  
Kenji Wakashima ◽  
Hee Young Kim ◽  
Shuichi Miyazaki ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Internal Friction ◽  
Shape Memory ◽  
Rolling Direction ◽  
Mechanical Analysis ◽  
Martensite Phase ◽  
Tensile Direction ◽  
Heat Treated ◽  
Tan Δ

Internal friction of Ti-24mol%Nb-3mol%Al (Ti-24Nb-3Al) shape memory alloy with a well-developed texture was investigated by dynamic mechanical analysis (DMA) in a tensile mode with a frequency of 1Hz and a temperature range of 123~423K. Ti-24Nb-3Al alloy fabricated by Ar arc-melting was cold-rolled with a reduction in thickness of 99% and then heat-treated at 1173K for 3.6ks in vacuum to develop a recrystallization texture. The martensitic transformation temperature and internal friction (tan δ) were evaluated under the stress amplitude of 36MPa. The tensile direction was selected to be the rolling direction (RD) and the transverse direction (TD). The specimen was β-single phase with a well-developed {112}β<110>β texture at room temperature and exhibited high damping during martensitic transformation and in the martensite phase. The relationship between internal friction and the tensile direction is discussed on the view point of the crystallography of the transformation.

Experimental Study on Mechanical Properties of Large NiTi Superelastic Shape Memory Alloy Bars

2021 ◽  
Author(s):  
Qiujun Ning ◽  
Lihua Zhu ◽  
Wei Han ◽  
Cheng Zhao
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Performance ◽  
Engineering Application ◽  
Test Results ◽  
Equivalent Viscous Damping ◽  
Heat Treated ◽  
Strength And Stiffness

Abstract This study intensively examined the mechanical properties of large-sized superelastic shape memory alloy (SMA) bars, mainly focusing on their self-centering and energy dissipation capabilities. A detailed investigation on the effects of the heat treatment strategy, loading rate, strain amplitude, cyclic loading, prestress, and diameter of the SMA bars on their mechanical performance—residual strain, energy dissipation, equivalent viscous damping ratios, strength, and stiffness—was conducted. Furthermore, the fracture microstructure of monotonic tensile specimens was analyzed via scanning electron microscopy. The results indicated that the optimally heat-treated SMA bars show good superelasticity. The mechanical properties were relatively stable under constant strain loading–unloading training, which should be considered in engineering applications. The test results provided basic experimental data support for the engineering application of large SMA bars.

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