Effects of Aging on the Microstructure and Phase Transformation Behavior of Cu-Al-Mn Shape Memory Alloy

2021 ◽  
Vol 882 ◽  
pp. 21-27
Author(s):  
Seyed Veghar Seyedmohammadi ◽  
Amin Radi ◽  
Guney Guven Yapici
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Aging Treatment ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Peak Aged Condition ◽  
Peak Aged ◽  
Rolled Condition ◽  
The One ◽  
Effects Of Aging

In the present work, the effects of artificial aging treatment on the transformation temperatures and hardness of Cu-Al-Mn shape memory alloy have been investigated. The aging processes have been performed on the one-time re-melted and 90% rolled samples. Differential scanning calorimetry reveals that reverse transformation is present for the re-melted sample which is aged at 400°C. However, in 90% rolled condition, this transformation takes place at 200°C and 300°C. Hardness examination shows that the aged specimens possess higher values in hardness in comparison to un-aged samples at all studied temperatures. Although, the peak-aged condition was demonstrated at 300°C for the re-melted sample, the rolled sample displayed increased hardness levels up to 500°C. Based on the DSC measurements and microstructural observations, it can be asserted that the thermo-mechanical processing including rolling plus aging at 300°C provides favorable transformation characteristics for shape memory behavior.

scholarly journals Effects of aging and thermal cycling on the microstructure and damping behaviors of a porous CuAlMn shape memory alloy

2020 ◽  
Vol 9 (4) ◽  
pp. 7020-7026
Author(s):  
Qian Wang ◽  
Liwei Wang ◽  
Jie Kang ◽  
Qingzhou Wang ◽  
Chunxiang Cui ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Thermal Cycling ◽  
Shape Memory ◽  
Effects Of Aging

Modeling of Electrical Resistivity Evolution Using Free Energy Analysis for NiTi Shape Memory Alloy Wires

2011 ◽  
Vol 311-313 ◽  
pp. 2282-2285
Author(s):  
Jian Jun Zhang
Keyword(s):  
Electrical Resistivity ◽  
Free Energy ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Free Energy Change ◽  
Energy Change ◽  
Niti Shape Memory Alloy ◽  
Scanning Calorimetry ◽  
Proposed Model ◽  
Free Energy Analysis

This paper presents a transformation kinetics model of NiTi shape memory alloy (SMA) wires based on electrical resistivity (ER) derivative study under the assumption that the derivative of electrical resistivity with respect to temperature is in linear relationship with the derivative of free energy change with respect to temperature. Free energy change and electrical resistivity properties of SMA are analyzed based on differential scanning calorimetry (DSC) experiments during phase transformation. The simulated evolution of electrical resistivity during thermomechanical transformation is presented using the proposed model.

Effect of Electroplastic Deformation on Martensitic Transformation in Coarse Grained and Ultrafine Grained Ni-Ti Shape Memory Alloy

2008 ◽  
Vol 584-586 ◽  
pp. 127-132 ◽  
Author(s):  
Anastasia E. Sergeeva ◽  
Daria Setman ◽  
Michael Zehetbauer ◽  
Sergey Prokoshkin ◽  
Vladimir V. Stolyarov
Keyword(s):  
Differential Scanning Calorimetry ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Cold Rolling ◽  
Shape Memory ◽  
Coarse Grained ◽  
Scanning Calorimetry ◽  
Structure Relaxation ◽  
Differential Scanning Calorimetry Method ◽  
Ultrafine Grained

The aim of this paper is the investigation of electroplastic deformation (EPD) and subsequent annealing influence on martensitic transformation in the shape memory Ni50.7Ti49.3 alloy. Using differential scanning calorimetry method it was shown that EPD at the low strain stimulates structure relaxation and recovers martensitic transformation in cooling, which is usually suppressed by cold rolling.

Cold Bending a Ni-Ti Shape Memory Alloy Wire

2015 ◽  
Vol 661 ◽  
pp. 98-104 ◽  
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.

scholarly journals Nanocrystal, phase transformation and microstructure of Ni50Ti50 shape memory alloy

2018 ◽  
Vol 24 (02) ◽  
pp. 22-25
Author(s):  
Dovchinvanchig M ◽  
Chunwang Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
One Step ◽  
Niti Matrix ◽  
Electronic Microscope

The nanocrystal, phase transformation and microstructure behavior of Ni50Ti50 shape memory alloy was investigated by scanning electronic microscope, X-ray diffraction and differential scanning calorimetry. The results showed that the microstructure of Ni-Ti binary alloy consists of the NiTi2 phase and the NiTi matrix phase. One-step phase transformation was observed alloy.

Nickel–titanium shape memory alloy mechanical components produced by investment casting

2018 ◽  
Vol 29 (19) ◽  
pp. 3748-3757 ◽  
Author(s):  
Jackson de Brito Simões ◽  
Carlos José de Araújo
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Investment Casting ◽  
Mechanical Characterization ◽  
Nickel Titanium ◽  
Compression Tests ◽  
Thermoelastic Martensitic Transformation ◽  
Scanning Calorimetry ◽  
Helical Springs ◽  
Mechanical Components

This work aimed to produce mechanical components of nickel–titanium shape memory alloys using investment casting processes. Then, in order to validate processing, different designs of nickel–titanium shape memory alloy components as staple implants, Belleville springs, meshes, helical springs, screws and hexagonal honeycombs were produced and submitted to thermal and mechanical characterization. Thermoelastic martensitic transformation of the nickel–titanium shape memory alloy parts was determined by differential scanning calorimetry and electrical resistance with temperature, while the superelastic behaviour was verified by cyclic tensile and compression tests. It has been demonstrated that the employed investment casting processes are suitable to manufacture nickel–titanium shape memory alloy mechanical components with simple and complicated designs as well as functional properties related to phase transformation and superelasticity.

NiTi Shape Memory Alloy Used for Multiple-Resetting Actuator for Fire Protection

2017 ◽  
Vol 907 ◽  
pp. 8-13 ◽  
Author(s):  
Lucian Burlacu ◽  
Nicanor Cimpoeşu ◽  
Nicoleta Monica Lohan ◽  
Leandru Gheorghe Bujoreanu
Keyword(s):  
Thermal Analysis ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Fire Protection ◽  
Room Temperature ◽  
Parent Phase ◽  
Niti Shape Memory Alloy ◽  
Scanning Calorimetry ◽  
Protection Systems ◽  
Executive Elements

The paper introduces the possibility to replace the “wet alloy”, used for sprinkler-triggering within automatic fire protection systems, with a shape memory alloy (SMA) type. The idea of the present application is based on the thermoelastic reversible martensitic transformation, governing SMA functioning, which has completely reversible character, and enables the occurrence of two-way shape memory effect (TWSME) after the application of a thermomechanical treatment called “training”. For this purpose a commercial NiTi rod, which was martensitic at room temperature, was subjected to thermal analysis tests, performed by differential scanning calorimetry (DSC) and dilatometry. Martensite (M) reversion to parent phase (A), during heating, was emphasized by an endothermic peak on the DSC thermogram and by a length shrinkage, on the dilatogram. The capacity to develop TWSME was revealed by the change in displacement-temperature variation, with increasing the number of training cycles. This stabilized fully reversible behavior recommends NiTi rods as executive elements of a new concept of resettable sprinkler for fire protection.

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