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.  

Experimental Validation and Numerical Simulation of Shape Memory Flat Wire Actuators

2014 ◽  
Author(s):  
Alexander Czechowicz ◽  
Sven Langbein
Keyword(s):  
Shape Memory Alloy ◽  
Boundary Conditions ◽  
Shape Memory ◽  
Smart Materials ◽  
Empirical Data ◽  
Dynamic Properties ◽  
Fatigue Behavior ◽  
Different Boundary Conditions ◽  
Heating And Cooling ◽  
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. This paper deals with the dynamic properties of SMA-actuators (Shape Memory Alloy) — characterized by their rate of heating and cooling procedures — that today can only be described insufficiently for different boundary conditions. Based on an analysis of energy fluxes into and out of the actuator, a numerical model of flat-wire used in a bow-like structure, implemented in MATLAB/SIMULINK, is presented. Different actuation parameters, depending on the actuator-geometry and temperature are considered in the simulation in real time. Additionally this publication sums up the needed empirical data (e.g. fatigue behavior) in order to validate the numerical two dimensional model and presents empirical data on SMA flat wire material.

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.

scholarly journals Impact fatigue behavior of superelastic NiTi shape memory alloy wires

2010 ◽  
Vol 528 (2) ◽  
pp. 764-769 ◽  
Author(s):  
J. Zurbitu ◽  
R. Santamarta ◽  
C. Picornell ◽  
W.M. Gan ◽  
H.-G. Brokmeier ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Fatigue Behavior ◽  
Niti Shape Memory Alloy ◽  
Impact Fatigue

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.

Thermomechanical and electrical response of a superelastic NiTi shape memory alloy cable

2020 ◽  
Vol 31 (19) ◽  
pp. 2229-2242 ◽  
Author(s):  
Muhammad M Sherif ◽  
Osman E Ozbulut
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Smart Materials ◽  
Complex Geometry ◽  
Electrical Response ◽  
High Energy ◽  
Temperature History ◽  
Niti Shape Memory Alloy ◽  
Outer Diameter ◽  
Resistance Change

Superelastic shape memory alloys are a unique class of smart materials that can recover up to 6% strains. Due to their appealing properties such as high energy dissipation and corrosion resistance, several researchers have assessed the use of such materials in numerous applications ranging from biomedical to civil engineering. This article investigates the thermomechanical and electrical response of a NiTi shape memory alloy cable with a complex configuration subjected to cyclic loading of various strain amplitudes ranging from 3% to 7%. The cable consists of several multi-layered strands with a cumulative outer diameter of 5.5 mm. The thermomechanical results indicate a good correlation of the change in cable temperature with the applied strains and maximum stresses. The temperature history can be used to map the degradation pattern of the shape memory alloy cable. In addition, due to the complex geometry of the cable, the global electrical resistance change does not predict the strain/stress state of the cable; however, it can be used to predict the onset of phase transformations.

Applying Isothermal Injection Moulding Process in the Manufacturing of Polymer Composite Reinforced with NiTi Shape Memory Alloy

2017 ◽  
Vol 380 ◽  
pp. 212-217 ◽  
Author(s):  
C.A. Araújo Mota ◽  
C.J. Araújo ◽  
A.G. Barbosa de Lima ◽  
Tony Herbert Freire de Andrade ◽  
D. Silveira Lira
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Product Quality ◽  
Polymer Composite ◽  
Smart Materials ◽  
Low Cost ◽  
Injection Pressure ◽  
Niti Shape Memory Alloy ◽  
Moulding Process ◽  
Injection Moulding Process

SMART materials have gained several applications in industries, especially aeronautical and biomedical. Therefore, the fabrication process of these materials must present quality in the completion and dimensioning, in addition to well established mechanical properties. In this sense, the Resin Transfer Molding (RTM) process is presented as an alternative to the manufacture of such products. This process presents advantages compared to other methods, such as, product quality and low cost. Thus, this work aims to model and simulate numerically the manufacturing process of polymer composite reinforced with NiTi shape memory alloy by RTM using the Ansys CFX commercial software. Results of pressure, velocity and volume fractions fields of the phases are presented and discussed. It was verified that the process parameters, like injection pressure and resin inlet and air outlet positions influenced the total time of the process and final product quality.

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