Adaptive Temperature Control of NiTi Shape Memory Alloy (SMA) for Dynamic Environmental Thermal Convection

2016 ◽  
Author(s):  
Nima Zamani ◽  
Mir Behrad Khamesee ◽  
Mohammad Ibraheem Khan
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Niti Shape Memory Alloy ◽  
Position Sensor ◽  
Convection Coefficient ◽  
Sma Actuators ◽  
The Past ◽  
Niti Sma ◽  
Sma Actuator ◽  
The Cost

In recent years, there have been an increased interest in manufacturing and controlling of smart materials such as NiTi Shape Memory for variety of applications in the fields of robotics, automotive, aerospace, and biomedical. In the past, there have been several studies done to control the position of SMA actuators, they mostly use a position sensor which directly measures the position [1][2]. The use of a position sensor adds substantially to the cost of an actuator unit. Moreover, there have been a few studies done in the field of self-sensing control of SMA actuators, however, they either assume a constant environmental conditions[3] or don’t consider the full complexity of the hysteresis behavior of SMAs [4]. Shape memory effect of SMAs, such as NiTi, are inherently due to a thermal process which leads to a phase transformation between the two solid phases of austenite and martensite [5]. The objective of this paper is to develop an adaptive electrical resistance feedback controller which controls the temperature of the NiTi SMA actuator based on the identified unknown heat convection coefficient.

A Multi-Purpose Method for SMA Actuator Development

2013 ◽  
Author(s):  
Sven Langbein ◽  
Alexander Czechowicz
Keyword(s):  
Standardized Testing ◽  
Shape Memory ◽  
Smart Materials ◽  
Research Work ◽  
Simulation Tools ◽  
Sma Actuators ◽  
Shape Memory Actuators ◽  
Computer Aided ◽  
Sma Actuator ◽  
Actual Shape

Shape memory alloys (SMA) are thermally activated smart materials. Due to their ability to change into a previously imprinted actual shape through the means of thermal activation, they are suitable as actuators for mechatronical systems. Despite of the advantages shape memory alloy actuators provide, these elements are only seldom integrated by engineers into mechatronical systems. Reasons are the complex characteristics, especially at different boundary conditions and the missing simulation- and design tools. Also the lack of knowledge and empirical data are a reason why development projects with shape memory actuators often lead to failures. Therefore, a need of developing methods, standardized testing of empirical properties and computer aided simulation tools is motivated. While computer-aided approaches have been discussed in further papers, as well as standardization potentials of SMA actuators, this paper focuses on a developing method for SMA actuators. The main part of the publication presents the logical steps which have to be passed, in order to develop an SMA actuator, considering several options like mechanical, thermal, and electrical options. As a result of the research work, the paper proves this method by one example in the field of SMA-valve technology.

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.

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

2009 ◽  
Vol 618-619 ◽  
pp. 319-323 ◽  
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.

Modeling and Tracking Control System of Shape Memory Alloy Actuator

2007 ◽  
Author(s):  
B. Y. Ren ◽  
B. Q. Chen
Keyword(s):  
Control System ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Tracking Control ◽  
Fuzzy Controller ◽  
Smart Structures ◽  
Constitutive Law ◽  
Hysteresis Model ◽  
Sma Actuators ◽  
Sma Actuator

The different Shape Memory Alloy (SMA) actuators have been widely used in the fields of smart structures. However, the accurate prediction of thermomechanical behavior of SMA actuators is very difficult due to the nonlinearity of inherence hysteresis of SMA. Therefore, the tracking control accuracy of SMA actuator is very important for the practical application of the SMA actuator. A dynamic hysteresis model of bias-type SMA actuator based on constitutive law developed by Brinson et al. and hysteresis model developed by Ikuta et al. is presented. The control systems composed of the Proportional Integral Derivative (PID) controller as well as a fuzzy controller or a fuzzy-PID composite controller for compensating the hysteresis is proposed. The effort of tracking control system is analyzed according to the simulation on the displacement of SMA actuator with the three kinds of controllers. The result can provide a reference for the application of SMA actuator in the fields of smart structures.

An Ablation Parameter Study and Micromachining of NiTi Based Shape Memory Alloy Using Femtosecond Laser

2007 ◽  
Author(s):  
Nitin Uppal ◽  
Panos S. Shiakolas
Keyword(s):  
Shape Memory Alloy ◽  
Femtosecond Laser ◽  
Shape Memory ◽  
Smart Materials ◽  
Interaction Mechanism ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Niti Shape Memory Alloy ◽  
Parameter Study ◽  
New Applications

The use of femtosecond lasers for the micromachining of engineering materials with micro and submicron size features is slowly but steadily increasing. This increase though presents challenges in understanding the interaction mechanism of femtosecond laser pulses with a material and defining process parameters for quality machining. This manuscript will present the setup for a 3DOF femtosecond laser microfabrication (FLM) system and its use in studying the ablation (single and multi shot) characteristics and incubation coefficient of nickel-titanium (NiTi) shape memory alloy. Understanding of these characteristics could allow for the identification of new applications of smart materials in the macro, micro, nano and MEMS domains.

Evaluating Fretting Wear on 3D-Printed α-, β-, γ- Additives Hybridized NiTi Shape Memory Alloy

2019 ◽  
Author(s):  
O. P. Bodunde ◽  
S. M. Gao ◽  
M. Qin ◽  
W. H. Liao
Keyword(s):  
Shape Memory ◽  
Wear Test ◽  
Xrd Analysis ◽  
Fretting Wear ◽  
Niti Shape Memory Alloy ◽  
Aerospace Applications ◽  
Niti Sma ◽  
Wear Mode ◽  
3D Printed ◽  
Niti Shape Memory Alloys

Abstract Nickel-Titanium (NiTi) shape memory alloys (SMAs) are a class of promising materials for bio-implant, transportation, and aerospace applications. These interesting applications of SMA are as a result of their ability to exhibit shape memory effect (SME) and super-elasticity (SE). SMAs, especially NiTi which has been proven to have good mechanical properties, are however limited by their operational fatigue as reported in the literature. In this paper, a near equiatomic NiTi SMA was hybridized with zirconium (Zr), molybdenum (Mo) and copper (Cu), which are available and economic viable α-, β-, γ- stabilizing additives suitable for NiTi SMAs. Each of Zr, Mo, Cu were hybridized separately with the bare near equiatomic NiTi SMA. The compositional requirements for each of the sub-hybrids (NiTi-α, NiTi-β, and NiTi-γ respectively) were experimentally determined to know the optimum composition which could indicate the presence of austenitic and martensitic phases. Scan electron microscopy (SEM) was performed on each of the hybridizing additives as well as the bare equiatomic NiTi to determine their particle sizes and investigate their compatibility (between 30 and 40 microns) with the 3D printer used in the study. X-ray diffractometric (XRD) analysis also was carried out on the bare SMA and its additives to determine the presence of B2 and B19’ peaks. Afterward, NiTi-α, NiTi-β, and NiTi-γ were 3D printed to produce fretting wear test specimens and finally, the fretting wear behaviors of the NiTi hybrids were studied in detail with the objective of testing their performances under fretting wear mode as it may be required for an application. A tungsten carbide counter-body was used. The results from the characterization through XRD indicated that all of α-, β-, γ- stabilizing additives with NiTi respectively showed the presence of B2 and B19’ in the inter-metallic phases. Details of wear microstructure were reported and its information could be useful for professionals who require hybridized NiTi alloys for various engineering applications.

scholarly journals OPTIMIZATION OF NICKEL CONTENT ON SOME PROPERTIES OF (NITI) SHAPE MEMORY ALLOY

2020 ◽  
Vol 1 (01) ◽  
pp. 40-47
Author(s):  
Aissa Bouaissi ◽  
Nabaa S Radhi ◽  
Karrar F. Morad ◽  
Mohammad H. Hafiz ◽  
Alaa Abdulhasan Atiyah
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Recovery ◽  
Fatigue Behavior ◽  
Nickel Content ◽  
Functionally Graded ◽  
Niti Shape Memory Alloy ◽  
Shape Effect ◽  
The Impact

Shape Memory Alloys (SMAs) are one of the most hopeful smart materials, especially, Nickel–Titanium (NiTi or Nitinol). These alloys are great and desirable due to their excellent reliability and behavior among all the commercially available alloys. In addition, strain recovery, (Ni–Ti) is granulated for a wide variety of medical uses because of its favorite properties such as fatigue behavior, corrosion resistance and biocompatibility. This paper explores the creation and the characterization of functionally graded (NiTi) materials. This work demonstrations the impact of Nickel contains changes on the characteristics of NiTi shape memory alloy, in order to obtain the suitable addition of Nickel contain, which gives the optimal balance between hardness, start and finish martensitic point, shape recovery and shape effect of alloys properties. These materials are prepared to obtain suddenly or gradually microstructure or composition differences inside the structure of one piece of material, the specimens made by powder metallurgy process and the influence of every layer of composite by; micro-hardness, transformation temperature DSC and shape effect. The hardness value and shape recovery decrease with increase nickel content. superior shape memory effect (SME) and shape recovery (SR) properties (i.e., 8.747, 10.270 for SMA-FGM1 SMA-FGM2 respectively, and SR is 1.735, 2.977 for SMA-FGM1 SMA-FGM2) respectively.  

Micromachining Characteristics of NiTi Based Shape Memory Alloy Using Femtosecond Laser

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Nitin Uppal ◽  
Panos S. Shiakolas
Keyword(s):  
Shape Memory Alloy ◽  
Femtosecond Laser ◽  
Shape Memory ◽  
Smart Materials ◽  
Morphological Changes ◽  
Wide Spectrum ◽  
Interaction Mechanism ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Niti Shape Memory Alloy

Femtosecond laser micromachining (FLM) is a relatively new and promising technology for the micromachining of a wide spectrum of engineering materials with micron and submicron size features. The interaction mechanism of femtosecond laser pulses with matter is not the same as that found in traditional lasers. This manuscript presents a detailed study of the ablation characteristics of a nickel-titanium (NiTi) shape memory alloy in air with femtosecond laser pulses. The single- and multishot ablation threshold fluence and the incubation coefficient (predicting the extent to which accumulation could take place in a material) are evaluated. In addition, morphological changes, such as the emergence of a ripple pattern, are discussed along with the identification of gentle and strong ablation phases. This study provides for the understanding and characterization of NiTi micromachining using FLM technology, which could aid in the identification of new applications for smart materials in the macro-, nano-, and microelectromechanical system domains using this technology.

Design Analysis in Frictional Fan Clutch Driven by SMA Spring

2011 ◽  
Vol 101-102 ◽  
pp. 7-10 ◽  
Author(s):  
Jian Zuo Ma ◽  
Peng Wei Liu
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Normal Pressure ◽  
Output Displacement ◽  
Sma Actuators ◽  
Torque Transmission ◽  
Sma Actuator ◽  
Sma Spring ◽  
Transmission Ability

This paper presents a fan clutch driven by SMA spring actuator. Based on shape memory effect of SMA, the operational principle of the fan clutch driven by SMA is introduced. The equation of the output displacement of SMA actuator in free stroke is derived. The normal pressure between driving and driven discs of the clutch generated by SMA actuators is analyzed to compute the torque transmission ability in the disc-type fan clutch. The characteristic of transmission torque is studied in detail. The results indicate that the change of temperatures has a tremendous influence on the normal pressure between driving and driven discs of the fan clutch, and the transmission torque of the fan clutch changes rapidly according to the temperatures of airflow from radiator.

Characterization of Anatase Coatings on NiTi Shape Memory Alloy by Plasma Electrolytic Oxidation Method

2011 ◽  
Vol 121-126 ◽  
pp. 3837-3841
Author(s):  
Li Hong Lu ◽  
Jing Wu Zhang ◽  
De Jiu Shen
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Plasma Electrolytic Oxidation ◽  
Niti Shape Memory Alloy ◽  
Aqua Regia ◽  
X Ray ◽  
Niti Sma ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

The anatase coatings was obtained by aqua regia dealloying and plasma electrolytic oxidation (PEO) method on NiTi shape memory alloy (SMA) substrate. The PEO manufacturability of NiTi SMA before and after dealloying was researched. The PEO surface morphologies of the aqua regia treated and untreated specimens were investigated with scanning electron microscopy (SEM). The composition of the PEO coatings was investigated with X-ray diffraction (XRD). The element concentration of the surface of the PEO-treated NiTi SMA was measured by an energy dispersive X-ray spectrometer (EDS). The results indicate that the pre-treatment technology by aqua regia dealloying can greatly improve the PEO manufacturability and the PEO morphologies of the NiTi SMA. The optimum dealloying parameters are at room temperature for 10 min. At this circumstance, the PEO manufacturability of the treated samples is most close to that of the industrial pure titanium. There are many honeycomb-like micro-pores in the surface of the PEO coatings, which act as discharging channels. The cracks are invisible in the SEM images of the PEO coatings. The PEO coatings formed on the NiTi is composed of Ti, Ni, Al, O, Au and P. The composition of the PEO coatings is mainly composed of NiTi phase and anatase phase.

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