Design of a Multiple-Actuation Shape Memory Alloy Pipe Coupler: Material Development and Characterization

2012 ◽  
Author(s):  
Majid Tabesh ◽  
John Rohmer ◽  
James G. Boyd ◽  
Dimitris C. Lagoudas ◽  
Kadri C. Atli ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Contact Pressure ◽  
Niti Alloy ◽  
Internal Surface ◽  
Alloy System ◽  
Longitudinal Direction ◽  
The State ◽  
Pipe System ◽  
Material Development

Shape memory alloy (SMA) pipe couplers use the shape memory effect to apply a contact pressure onto the surface of the pipes to be coupled. In the current research, an SMA pipe coupler is designed, fabricated and tested. The thermally induced contact pressure depends on several factors such as the dimensions and properties of the coupler-pipe system. An in-house developed NiTi alloy system is considered for the coupler. The coupling pressure is measured using strain gages mounted on the internal surface of an elastic steel ring. Thermal actuation response of the coupler is determined under both stressed and stress-free conditions. In addition, the state of anisotropy is investigated in the coupler by characterizing samples in the longitudinal and transverse directions. Unlike the commercially available NiTiNb couplers, the NiTi coupler demonstrates a multiple actuation response and higher contact pressure. The state of anisotropy is investigated in the couplers by characterizing samples in the longitudinal and transverse directions. The results show no change in transformation temperatures with respect to two perpendicular transverse and longitudinal directions, however, the material can undergo higher transformation strains in the longitudinal direction.

Design, fabrication, and testing of a multiple-actuation shape memory alloy pipe coupler

2017 ◽  
Vol 29 (6) ◽  
pp. 1165-1182 ◽  
Author(s):  
Majid Tabesh ◽  
James Boyd ◽  
Kadri Can Atli ◽  
Ibrahim Karaman ◽  
Dimitris Lagoudas
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Contact Pressure ◽  
Analytical Modeling ◽  
Niti Alloy ◽  
Internal Surface ◽  
Longitudinal Direction ◽  
Strain Gages ◽  
Thermal Actuation ◽  
High Contact Pressure

Shape memory alloy pipe couplers use the shape memory effect to apply a contact pressure onto the surface of the pipes to be coupled. In the current research, a shape memory alloy pipe coupler is designed, fabricated, and tested. An in-house developed NiTi alloy is used for the coupler. The coupler is initially designed using finite element as well as analytical modeling to accommodate the required actuation temperature and contact pressure properties. The coupling pressure is then measured using strain gages mounted on the internal surface of an elastic steel ring. The thermal actuation response of the coupler is measured under both stressed and stress-free conditions. In addition, the state of anisotropy is investigated in the coupler by characterizing samples in the longitudinal and transverse directions. The NiTi coupler demonstrates a multiple-actuation response and a high contact pressure. The results show no change in transformation temperatures with respect to two perpendicular transverse and longitudinal directions. However, the material can undergo higher transformation strains in the longitudinal direction.

scholarly journals Key Properties of a Bioactive Ag-SiO2/TiO2 Coating on NiTi Shape Memory Alloy as Necessary at the Development of a New Class of Biomedical Materials

2021 ◽  
Vol 22 (2) ◽  
pp. 507
Author(s):  
Mateusz Dulski ◽  
Robert Gawecki ◽  
Sławomir Sułowicz ◽  
Michal Cichomski ◽  
Alicja Kazek-Kęsik ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Dermal Fibroblast ◽  
Niti Alloy ◽  
Bacterial Biofilm ◽  
Niti Shape Memory Alloy ◽  
Normal Human Dermal Fibroblast ◽  
Water Contact ◽  
Nano Coating

Recent years have seen the dynamic development of methods for functionalizing the surface of implants using biomaterials that can mimic the physical and mechanical nature of native tissue, prevent the formation of bacterial biofilm, promote osteoconduction, and have the ability to sustain cell proliferation. One of the concepts for achieving this goal, which is presented in this work, is to functionalize the surface of NiTi shape memory alloy by an atypical glass-like nanocomposite that consists of SiO2-TiO2 with silver nanoparticles. However, determining the potential medical uses of bio(nano)coating prepared in this way requires an analysis of its surface roughness, tribology, or wettability, especially in the context of the commonly used reference coat-forming hydroxyapatite (HAp). According to our results, the surface roughness ranged between (112 ± 3) nm (Ag-SiO2)—(141 ± 5) nm (HAp), the water contact angle was in the range (74.8 ± 1.6)° (Ag-SiO2)—(70.6 ± 1.2)° (HAp), while the surface free energy was in the range of 45.4 mJ/m2 (Ag-SiO2)—46.8 mJ/m2 (HAp). The adhesive force and friction coefficient were determined to be 1.04 (Ag-SiO2)—1.14 (HAp) and 0.247 ± 0.012 (Ag-SiO2) and 0.397 ± 0.034 (HAp), respectively. The chemical data showed that the release of the metal, mainly Ni from the covered NiTi substrate or Ag from Ag-SiO2 coating had a negligible effect. It was revealed that the NiTi alloy that was coated with Ag-SiO2 did not favor the formation of E. coli or S. aureus biofilm compared to the HAp-coated alloy. Moreover, both approaches to surface functionalization indicated good viability of the normal human dermal fibroblast and osteoblast cells and confirmed the high osteoconductive features of the biomaterial. The similarities of both types of coat-forming materials indicate an excellent potential of the silver-silica composite as a new material for the functionalization of the surface of a biomaterial and the development of a new type of functionalized implants.

Computational thermodynamics of the CoNiGa high temperature shape memory alloy system

Calphad ◽  
2014 ◽  
Vol 45 ◽  
pp. 167-177 ◽  
Author(s):  
Arpita Chari ◽  
Ebubekir Dogan ◽  
Anjana Talapatra ◽  
Avinash. R. Chivukula ◽  
Andres Garay ◽  
...  
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Alloy System ◽  
Computational Thermodynamics

EFFECTS OF PARTICLE SIZE AND SINTERING TEMPERATURE ON SUPERELASTICITY BEHAVIOR OF NiTi SHAPE MEMORY ALLOY USING NANOINDENTATION

2021 ◽  
pp. 2150024
Author(s):  
C. VELMURUGAN ◽  
V. SENTHILKUMAR
Keyword(s):  
Particle Size ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Sintering Temperature ◽  
Niti Alloy ◽  
Indentation Load ◽  
Niti Shape Memory Alloy ◽  
Recovery Ratio ◽  
Work Recovery ◽  
Niti Sma

The present study investigates the superelasticity properties of spark plasma sintered (SPS) nickel titanium shape memory alloy (NiTi SMA) with the influence of sintering temperature and particle size. The nanoindentation is conducted on the surface of the NiTi SMA at various loads such as 100, 300 and 500[Formula: see text]mN. The nanoindentation technique determines the quantitative results of elasto-plastic properties such as depth recovery in the form of superelasticity, stiffness, hardness and work recovery ratio from load–depth ([Formula: see text]–[Formula: see text]) data during loading and unloading of the indenter. Experimental findings show that the depth and work recovery ratio increases with the decrease of indentation load and particle size. In contrast, increasing the sintering temperature exhibited a better depth and work recovery due to the removal of pores which could enhance the reverse transformation. The contact stiffness is influenced by [Formula: see text] which leads to attain a maximum stiffness at the highest load (500[Formula: see text]mN) and particle size (45[Formula: see text][Formula: see text]m) along with the lowest sintering temperature (700∘C). NiTi alloy exhibited a maximum hardness of 9.46[Formula: see text]GPa when subjected to indent at the lowest load and particle size sintered at 800∘C. The present study reveals a better superelastic behavior in NiTi SMA by reducing the particle size and indentation load associated with the enhancement of sintering temperature.

Viscoelastic behavior of epoxy resin reinforced with shape-memory-alloy wires

2020 ◽  
pp. 1045389X2097549
Author(s):  
Niloufar Bagheri ◽  
Mahmood M Shokrieh ◽  
Ali Saeedi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Epoxy Resin ◽  
Volume Fraction ◽  
Niti Alloy ◽  
Micromechanical Model ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Reinforced Polymer ◽  
Small Volume Fraction

The effect of NiTi alloy long wires on the viscoelastic behavior of epoxy resin was investigated by utilizing the dynamic mechanical analysis (DMA) and a novel micromechanical model. The present model is capable of predicting the viscoelastic properties of the shape-memory-alloy (SMA) reinforced polymer as a function of the SMA volume fraction, initial martensite volume fraction, pre-strain level in wires, and the temperature variations. The model was verified by conducting experiments. Good agreement between the theoretical and experimental results was achieved. A parametric study was also performed to investigate the effect of SMA parameters. According to the results, by the addition of a small volume fraction of SMA, the storage modulus of the composite increases significantly, especially at higher temperatures. Moreover, applying a 4% pre-strain caused a 10% increase in the maximum value of the loss factor of the SMA reinforced epoxy in comparison with the 0% pre-strained SMA reinforced epoxy.

Thermal Properties, Microstructure and Microhardness of Cu–Al–Co Shape Memory Alloy System

2014 ◽  
Vol 67 (4) ◽  
pp. 595-600 ◽  
Author(s):  
Yıldırım Aydoğdu ◽  
Ferdi Kürüm ◽  
Mediha Kök ◽  
Zehra Deniz Yakinci ◽  
Ayşe Aydoğdu
Keyword(s):  
Thermal Properties ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Alloy System

Nonlinear dynamics of a rotordynamic nonsmooth shape memory alloy system

2013 ◽  
Vol 332 (3) ◽  
pp. 608-621 ◽  
Author(s):  
Leandro C. Silva ◽  
Marcelo A. Savi ◽  
Alberto Paiva
Keyword(s):  
Nonlinear Dynamics ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Alloy System

Corrosion Kinetics of Laser Treated NiTi Shape Memory Alloy Biomaterials

1996 ◽  
Vol 459 ◽  
Author(s):  
F. Villermaux ◽  
I. Nakatsugawa ◽  
M. Tabrizian ◽  
D. L. Piron ◽  
M. Meunier ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Laser Treatment ◽  
Niti Alloy ◽  
Niti Shape Memory Alloy ◽  
Surgical Implants ◽  
Hank’S Solution ◽  
Kinetics Of ◽  
Human Fluids

ABSTRACTNiTi shape memory alloy presents interesting mechanical properties as surgical implants. However, due to its high amount of Ni which may dissolve and release toxic ions in human fluids, the medical use of this material is a great concern. We have developed a laser treatment which modifies the oxide layer and enhances uniform and localised corrosion resistance of NiTi alloy.In this paper we further analysed the effect of this treatment with potentiostatic and AC impedance measurements in physiological Hank's solution. We conclude that the laser treatment creates a stable passive film which results in improved corrosion resistance of this alloy.

scholarly journals Experimental Analysis of NiTi Alloy during Strain-Controlled Low-Cycle Fatigue

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4455
Author(s):  
Pedro Cunha Lima ◽  
Patrícia Freitas Rodrigues ◽  
Ana Sofia Ramos ◽  
José D. M. da Costa ◽  
Francisco Manuel Braz Fernandes ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Low Cycle Fatigue ◽  
Niti Alloy ◽  
Niti Shape Memory Alloy ◽  
Cycle Fatigue ◽  
Maximum Deformation ◽  
Transmission Electron ◽  
Before And After

The interaction between the stress-induced martensitic transformation and resistivity behavior of superelastic NiTi shape memory alloy (SMA) was studied. Strain-controlled low-cycle fatigue up to 6% was monitored by in situ electrical resistivity measurements. The experimental results show that a great motion of martensite fronts results in a significant accumulation of defects, as evidenced by transmission electron microscopy (TEM), before and after the tensile cycles. This gives rise to an overall increase of the resistivity values up to the maximum deformation. Therefore, the research suggests that shape memory alloy wire has great potential as a stress sensor inside bulk materials.

Study on Corrosion Behavior of Ti-Ni-Nb Shape Memory Alloy and 1Cr18Ni9Ti Stainless Steel Aeroplane Pipe System

2013 ◽  
Vol 668 ◽  
pp. 808-813
Author(s):  
Jun Xiu Shi ◽  
Jian Hua Liu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Nacl Solution ◽  
Corrosion Morphology ◽  
Pipe System ◽  
Pipe Coupling

The susceptibility to stress corrosion cracking (SCC) and galvanic corrosion of an aeroplane pipe made of 1Cr18Ni9Ti connected with a pipe coupling that made of Ti-Ni-Nb shape memory alloy were evaluated. SCC test was completed under simulated service environment in 6% NaCl solution through a self-designed corrosive system. Galvanic corrosion behavior of Ti-Ni-Nb/1Cr18Ni9Ti couple was conducted in 3.5% NaCl solution at 30°C, in which galvanic corrosion current (Ig) and galvanic corrosion potential (Eg) were monitored. The corrosion morphology was observed by using scanning electronic microscope (SEM) and optical microscope (OM) after SCC test and galvanic test. It was showed that no obvious corrosion was detected on the surface of the whole pipe system after the simulated test. The two metals showed excellent resistance to SCC based on the section morphology observation. The average galvanic corrosion current of 1Cr18Ni9Ti/Ti-Ni-Nb couple was 0.13µA/cm2. No obvious corrosion pitting was detected on the surface of the two alloys by OM observation. Therefore, 1Cr18Ni9Ti pipe was safely connected with Ti-Ni-Nb pipe coupling in aeroplane pipe system.

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