Comparative Studies of Work-developing Capacity of Shape Memory Alloys (SMA) and Polymers

2020 ◽  
Vol 70 (12) ◽  
pp. 4366-4371
Keyword(s):  
Glass Transition ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Comparative Studies ◽  
Specific Work ◽  
Work Output ◽  
Glass Transitions ◽  
Generating Capacity ◽  
Alloy Heat

The thermodynamic and work-generating behaviours of a Cu-14.86 Zn-5.81 Al (mass. %) shape memory alloy (SMA) and a three-layer PET heat shrinkable sheath were comparatively discussed. The experimental CuZnAl SMA under study experienced a reversible martensitic transformation and was able to lift over 4.8 mm, during heating-cooling cycles, a load which was 463 times heavier than the specimen. During heating, the PET fragments underwent up to three glass transitions and the PET ring-shaped specimens were able to lift over 3 mm, a load which was 1571 times heavier. By comparing the work generating capacity of CuZnAl SMA and PET heat shrinkable sheath, defined as the ratio between total absorbed enthalpy and specific work output, it was found out that the former has been ten times less effective than the latter. Keywords: shape memory alloy, heat-shrinkable sheath, work-generating shape memory effect, martensitic transformation, glass transition

Phase Constitution and Martensitic Transformation Behavior of Au-51Ti-18Co Biomedical Shape Memory Alloy Heat-Treated at 1173K to 1373K

2016 ◽  
Vol 879 ◽  
pp. 256-261 ◽  
Author(s):  
Taywin Buasri ◽  
Hyun Bo Shim ◽  
Masaki Tahara ◽  
Tomonari Inamura ◽  
Kenji Goto ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Heat Treatment Temperature ◽  
Transformation Strain ◽  
Treatment Temperature ◽  
Transformation Behavior ◽  
Heat Treated ◽  
Alloy Heat

Phase constitution and martensitic transformation behavior were investigated for a Au–51Ti–18Co alloy heat-treated at 1173 K to 1373 K for 3.6 ks. The Au–51Ti–18Co alloy was fabricated by Ar arc-melting technique and subsequently by hot-forging at 1423 K for 10.8 ks. X-ray diffraction analysis revealed that B2 parent phase, B19 martensite phase and AuTi3 simultaneously appeared regardless of the heat-treatment temperatures. By increasing the heat-treatment temperature, the volume fraction of AuTi3 was slightly reduced. Besides, the lattice transformation strain which was calculated from the precisely-determined lattice parameters was evaluated to be 7 % in the Au–51Ti–18Co alloy in all the heat-treated conditions. This value is comparable to that of NiTi practical alloys. From differential scanning calorimetry (DSC) analysis, reverse martensitic transformation temperature was slightly increased with the heat-treatment temperature. From the lattice transformation strain point of views, the Au–51Ti–18Co has a large potential for novel biomedical shape memory alloy.

Micro and Macromechanical Study of Stress-Induced Martensitic Transformation in a Cu-Al-Be Polycrystalline Shape Memory Alloy

2006 ◽  
Vol 509 ◽  
pp. 87-92 ◽  
Author(s):  
F.M. Sánchez ◽  
G. Pulos
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Vector Fields ◽  
Displacement Vector ◽  
Optical Microscope ◽  
Image Sequences ◽  
Tension Test ◽  
Loading Device ◽  
Stress States

An experimental investigation of the micro and macromechanical stress-induced martensitic transformation in a Cu-Al-Be polycrystalline shape memory alloy is undertaken using a uniaxial tension test. Digital images are acquired at different stress states. The image sequences are analyzed to estimate the optical flow to get displacement vector fields. The experiments are carried out on a miniature hydraulic loading device mounted under an optical microscope. The stress-strain curves and associated images show stress-induced martensitic transformation in specific grains. Displacement vector fields for the polycrystalline shape memory alloy are obtained. They are inhomogeneous due to the martensitic transformation and inter-granular interactions.

scholarly journals Effect of Nd Addition on the Microstructure and Martensitic Transformation of Ni-Ti Shape Memory Alloys

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
M. Dovchinvanchig ◽  
C. W. Zhao ◽  
S. L. Zhao ◽  
X. K. Meng ◽  
Y. J. Jin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Earth Element ◽  
Transformation Behavior ◽  
Nd Addition ◽  
One Step ◽  
Niti Matrix ◽  
Start Temperature

The effect of rare earth element Nd addition on the microstructure and martensitic transformation behavior of Ni50Ti50−xNdx(x=0, 1, 3, 7, 20) shape memory alloy was investigated experimentally. The results showed that the microstructure of Ni-Ti-Nd ternary alloy consists of the NiNd phase and the NiTi matrix. One-step martensitic transformation was observed in all alloys. The martensitic transformation start temperatureMsincreased gradually with increasing Nd content for Ni-Ti-Nd alloys.

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.

scholarly journals In-situ TEM Observation of γ→ε Martensitic Transformation during Tensile Straining in an Fe–Mn–Si Shape Memory Alloy

1997 ◽  
Vol 38 (12) ◽  
pp. 1072-1077 ◽  
Author(s):  
Bohong Jiang ◽  
Tsugio Tadaki ◽  
Hirotaro Mori ◽  
T. Y. Hsu (Xu Zuyao)
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory
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