Effect of Alloy Composition on Microstructure and Martensitic Transformation Temperature of a Zr-Cu Shape Memory Alloy

2019 ◽  
Vol 6 (4) ◽  
pp. 93-98
Author(s):  
Hitoo Tokunaga ◽  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Transformation Temperature ◽  
Alloy Composition ◽  
Martensitic Transformation Temperature

Effect of the Addition of Gd on Ni53Mn22Co6Ga19 High-Temperature Shape Memory Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 2095-2098
Author(s):  
Yun Qing Ma ◽  
Shui Yuan Yang ◽  
San Li Lai ◽  
Shi Wen Tian ◽  
Cui Ping Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Earth Element ◽  
Stress And Strain ◽  
Martensitic Transformation Temperature ◽  
Rich Phase ◽  
Shape Memory Properties

The rare earth element Gd is added to Ni53Mn22Co6Ga19 high-temperature shape memory alloy to refine the grain size and adjust the distribution of γ phase, and their microstructure, martensitic transformation behaviors, mechanical and shape memory properties were investigated. The results show that the grain size is obviously decreased and the γ phase tends to segregate at grain boundaries with increasing Gd content. Small amounts of Gd-rich phase were formed with 0.1 at.% Gd addition. The martensitic transformation temperature abruptly increases with 0.1 at.% Gd addition, then almost keeps constant with further increasing Gd content. The addition of 0.1 at.% Gd is proved to be beneficial to both tensile stress and strain before fracture, but negative to the shape-memory effect.

Phase Transformation in Ti-Ni-Ta Shape Memory Alloy

2007 ◽  
Vol 130 ◽  
pp. 147-150 ◽  
Author(s):  
Zdzisław Lekston ◽  
Tomasz Goryczka
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Medical Application ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Martensitic Transformation Temperature ◽  
X Ray ◽  
Solution Treated

A new Ti50Ni48.7Ta1.3 shape memory alloy was designed for medical application. In order to influence the martensitic transformation temperature the alloy was solution treated and additionally aged at 400oC for various time. Phase transformation was studied applying differential scanning calorimeter (DSC) and X-ray diffraction techniques. The ageing causes that the martensitic transformation occurs in two steps: B2↔R↔B19’ during cooling and heating. During cooling the transformations: B2→R and R→B19’ are well separated whereas on heating they are overlapped. Also ageing causes a shift of temperatures of the martensitic transformation into the higher region. It is due to the precipitation process. Precipitates of the Ni4Ti3 phase were observed. Applied thermal treatment leads to shift of the transformation temperatures below temperature of a human body. This makes the Ti-Ni-Ta alloy attractive for application in medicine.

Effect of Ce Addition on Martensitic Transformation Behavior of TiNi Shape Memory Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 1973-1976 ◽  
Author(s):  
Ailian Liu ◽  
Xianglong Meng ◽  
Wei Cai ◽  
Lian Cheng Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Shape Memory ◽  
Energy Dispersive Spectroscopy ◽  
Transformation Temperature ◽  
Martensitic Transformation Temperature ◽  
Transformation Behavior ◽  
Scanning Calorimetry ◽  
Ce Content

The effect of cerium addition on the martensitic transformation behavior and microstructure of Ti50-x/2Ni50-x/2Cex (x=0, 0.5, 2, 5 and 10at.%) alloys have been studied by differential scanning calorimetry (DSC) and energy dispersive spectroscopy (EDS). The results show that the addition of cerium affects the martensitic transformation temperature obviously. With the increase of Ce content, the phase transformation temperatures first increase rapidly and then decrease slightly, which may be attributed to the change of the Ni/Ti ratio in matrix. Moreover, the dispersed Ce-riched second particles with various morphologies are observed in TiNiCe alloys.

Martensitic Transformation and Magnetic-Field-Induced Strain in Magnetic Shape Memory Alloy NiMnGa Melt-Spun Ribbon

2005 ◽  
Vol 475-479 ◽  
pp. 2009-2012 ◽  
Author(s):  
Shi Hai Guo ◽  
Yang Huan Zhang ◽  
Bai Yun Quan ◽  
Jian Liang Li ◽  
Xin Lin Wang
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Internal Stress ◽  
Melt Spinning ◽  
Martensitic Transformation Temperature ◽  
Magnetic Shape Memory ◽  
Magnetic Shape Memory Alloy ◽  
Melt Spun

A non-stoichiometric polycrystalline Ni50Mn27Ga23 magnetic shape memory alloy was prepared by melt-spinning technology. The effects of melt-spinning on the martensitic transformation and magnetic-field-induced strain (MFIS) of the melt-spun ribbon were investigated. The experimental results show that the melt-spun ribbon undergoes the thermal-elastic martensitic transformation and exhibits the thermo-elastic shape memory effect. But the martensitic transformation temperature decreases and Curie temperature remains unchanged. A particular internal stress induced by melt-spinning made a texture structure in the melt-spun ribbon, which made the melt-spun ribbon obtain larger transition-induced strain and MFIS. The internal stress was released under cycling of magnetic field. This resulted in a decrease of MFIS of the melt-spun ribbon.

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