scholarly journals Effect of Solution Treatment on the Shape Memory Functions of (TiZrHf)50Ni25Co10Cu15 High Entropy Shape Memory Alloy

Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1027 ◽  
Author(s):  
Hao-Chen Lee ◽  
Yue-Jin Chen ◽  
Chih-Hsuan Chen
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Lattice Distortion ◽  
Functional Performance ◽  
Solution Treatment ◽  
Memory Functions ◽  
High Entropy ◽  
The Matrix ◽  
Entropy Effect

This study investigated the effects of solution treatment at 1000 °C on the transformation behaviors, microstructure, and shape memory functions of a novel (TiZrHf)50Ni25Co10Cu15 high entropy shape memory alloy (HESMA). The solution treatment caused partial dissolution of non-oxygen-stabilized Ti2Ni-like phase. This phenomenon resulted in the increment of (Ti, Zr, Hf) content in the matrix and thus increment of the Ms and Af temperatures. At the same time, the solution treatment induced a high entropy effect and thus increased the degree of lattice distortion, which led to increment of the friction force during martensitic transformation, resulting in a broad transformation temperature range. The dissolution of the Ti2Ni-like phase also improved the functional performance of the HESMA by reducing its brittleness and increasing its strength. The experimental results presented in this study demonstrate that solution treatment is an effective and essential way to improve the functional performance of the HESMA.

Investigation on Ce Addition on Microstructure and Martensitic Transformation of a Ti51Ni49 Shape Memory Alloy

2016 ◽  
Vol 852 ◽  
pp. 28-32
Author(s):  
Ai Lian Liu ◽  
Nan Nan Mao ◽  
Jia Wen Xu ◽  
Wei Cai
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Ternary Alloys ◽  
Tini Alloy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
The Matrix ◽  
One Step ◽  
Electronic Microscope

The effect of rare earth element Ce addition on the microstructure and martensitic transformation behavior of Ti51Ni49 shape memory alloy was investigated by scanning electronic microscope (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results show that the microstructure of TiNiCe ternary alloy consists of Ti2Ni phase, CeNi phase and the matrix. One-step martensitic transformation is observed in quenched TiNiCe ternary alloys, which is the same as that in quenched TiNi binary alloys. The martensitic transformation temperatures of Ti-rich TiNi alloy hardly increase with Ce addition.

The Microstructure and Properties of Ti50Ni47Fe3 and Ti50Ni46.75Fe3Cr0.25 Shape Memory Alloy

2013 ◽  
Vol 631-632 ◽  
pp. 326-330
Author(s):  
Xiao Yu Kang ◽  
Yan Feng Li ◽  
Xiang Qian Yin ◽  
Hao Feng Xie ◽  
Xu Jun Mi
Keyword(s):  
Mechanical Property ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Properties ◽  
The Matrix ◽  
Ti2ni Phase ◽  
Better Than

Comparing with Ti50Ni47Fe3alloys, the influences of Cr on the mechanical and shape memory properties of Ti50Ni47Fe3alloys are investigated by study on phase transformation and microstructure analysis. The results show that Ti50Ni47Fe3and Ti50Ni46.75Fe3Cr0.25shape memory alloys exhibit two-stage martensitic transformation. The transformation temperatures decrease with the addition of Cr. The microstructure of the Ti50Ni47Fe3and Ti50Ni46.75Fe3Cr0.25alloys consists of TiNi matrix, Ti2Ni phase. Fe element prefers to substitute for Ni in the matrix than black particles. Cr all substitute for Ni in the matrix and not be analyzed in the Ti2Ni phase. The mechanical property of Ti50Ni46.75Fe3Cr0.25alloy is better than Ti50Ni47Fe3alloy.

Effect of Solution Treatment on the Microstructure and Reverse Martensitic Transformation Behavior of a Novel Porous CuAlMn Shape Memory Alloy

2011 ◽  
Vol 421 ◽  
pp. 173-178
Author(s):  
Qing Zhou Wang ◽  
Chun Xiang Cui ◽  
Na Jun Yan ◽  
Qian Wang
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Internal Friction ◽  
Shape Memory ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Transformation Behavior ◽  
Reverse Martensitic Transformation ◽  
Temperature Ranges

A novel porous CuAlMn shape memory alloy (SMA) has been successfully fabricated by sintering-dissolution process. Effect of solution treatment on the microstructure and the reverse martensitic transformation (MT) behavior of the resulting specimens are investigated by means of SEM, optical microscope, DSC and internal friction (IF). The results show that with increasing solution temperature, the content and the size as well as the arrangement order of martensite in matrix increase. The reverse MT behavior follows different dependences on solution temperature and solution time at different temperature ranges. The related mechanisms are discussed in terms of the changes of the content of martensite and the concentration of quenched-in vacancies.

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.

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