Transformation Temperatures, Shape Memory and Magnetic Properties of Hafnium Modified Ti-Ta Based High Temperature Shape Memory Alloys

AbstractIn this study the modification effect of Hf content on the shape memory properties and magnetic permeability of a 75.5-77Ti-20Ta-3-4.5Hf alloy system has been systematically studied by DSC, three-point bend test, vector network analyzer and XRD. The martensitic transformation temperature, heat of reaction and recovery strain increases with the increase of hafnium and tantalum content. A stable high temperature shape memory effect was observed (Ms = 385–390 °C) during the two thermal cycles between 20 °C and 725 °C. Transformation temperatures and heats of reaction were determined by DSC measurements. Recovery strain was determined by three-point bend testing. Also an alloy, 70Ti-26Ta-4Hf, with higher tantalum content was produced to observe the effect of Ta on the shape memory properties. Permeability increases gradually from 1.671 to 1.919 with increasing content of hafnium modification and remains stable in the frequency range of 450 MHz to 1 GHz.

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Effect of Stoichiometry on Shape Memory Properties and Functional Stability of Ti–Ni–Pd Alloys

Materials ◽

10.3390/ma12050798 ◽

2019 ◽

Vol 12 (5) ◽

pp. 798 ◽

Cited By ~ 4

Author(s):

Yuki Hattori ◽

Takahiro Taguchi ◽

Hee Kim ◽

Shuichi Miyazaki

Keyword(s):

High Temperature ◽

Martensitic Transformation ◽

Shape Memory Alloys ◽

Thermal Cycling ◽

Shape Memory ◽

Stoichiometric Composition ◽

Atomic Ratio ◽

Transformation Temperatures ◽

Shape Memory Properties ◽

Ti Content

Ti–Ni–Pd shape memory alloys are promising candidates for high-temperature actuators operating at above 373 K. One of the key issues in developing high-temperature shape memory alloys is the degradation of shape memory properties and dimensional stabilities because plastic deformation becomes more pronounced at higher working temperature ranges. In this study, the effect of the Ti:(Ni + Pd) atomic ratio in TixNi70−xPd30 alloys with Ti content in the range from 49 at.% to 52 at.% on the martensitic transformation temperatures, microstructures and shape memory properties during thermal cycling under constant stresses were investigated. The martensitic transformation temperatures decreased with increasing or decreasing Ti content from the stoichiometric composition. In both Ti-rich and Ti-lean alloys, the transformation temperatures decreased during thermal cycling and the degree of decrease in the transformation temperatures became more pronounced as the composition of the alloy departed from the stoichiometric composition. Ti2Pd and P phases were formed during thermal cycling in Ti-rich and Ti-lean alloys, respectively. Both Ti-rich and Ti-lean alloys exhibited superior dimensional stabilities and excellent shape memory properties with higher recovery ratio and larger work output during thermal cycling under constant stresses when compared with the alloys with near-stoichiometric composition.

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Thermal cycling effects in high temperature Cu–Al–Ni–Mn–B shape memory alloys

Journal of Materials Research ◽

10.1557/jmr.1997.0305 ◽

1997 ◽

Vol 12 (9) ◽

pp. 2288-2297 ◽

Cited By ~ 8

Author(s):

J. Font ◽

J. Muntasell ◽

J. Pons ◽

E. Cesari

Keyword(s):

High Temperature ◽

Martensitic Transformation ◽

Shape Memory Alloys ◽

Thermal Cycling ◽

Shape Memory ◽

Parent Phase ◽

Aluminum Boride ◽

Transformation Temperatures ◽

Dsc Measurements ◽

Number Of Cycles

The effects of thermal cycling through the martensitic transformation have been studied in three Cu–Al–Ni–Mn–B high temperature shape memory alloys. An increase of the martensitic transformation temperatures with the number of cycles (up to ∼7 K after 60 cycles) has been generally observed by DSC measurements. The microstructure of these alloys is rather complicated, with the presence of big manganese or aluminum boride particles and small boron precipitates, as well as the formation of dislocations during thermal cycling. By means of aging experiments, it has been shown that the evolution of transformation temperatures during cycling is mainly due to the step-by-step aging in parent phase accompanying the thermal cycling, and that the dislocations formed during cycling have only a very small effect, at least up to 60 cycles.

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Computational thermodynamics of the CoNiGa high temperature shape memory alloy system

Calphad ◽

10.1016/j.calphad.2013.12.005 ◽

2014 ◽

Vol 45 ◽

pp. 167-177 ◽

Cited By ~ 4

Author(s):

Arpita Chari ◽

Ebubekir Dogan ◽

Anjana Talapatra ◽

Avinash. R. Chivukula ◽

Andres Garay ◽

...

Keyword(s):

High Temperature ◽

Shape Memory Alloy ◽

Shape Memory ◽

Alloy System ◽

Computational Thermodynamics

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Effect of Ni-Content on the Transformation Temperatures in NiTi-20 at. % Zr High Temperature Shape Memory Alloys

Metals ◽

10.3390/met7110511 ◽

2017 ◽

Vol 7 (11) ◽

pp. 511 ◽

Cited By ~ 14

Author(s):

Matthew Carl ◽

Jesse Smith ◽

Brian Van Doren ◽

Marcus Young

Keyword(s):

High Temperature ◽

Shape Memory Alloys ◽

Shape Memory ◽

Transformation Temperatures ◽

Ni Content

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Microstructure, thermomechanical and shape memory properties of two-phase Ni–Mn–Fe–Ga high-temperature shape memory alloys with B addition

Intermetallics ◽

10.1016/j.intermet.2013.01.007 ◽

2013 ◽

Vol 37 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Shuiyuan Yang ◽

Cuiping Wang ◽

Zhan Shi ◽

Xingjun Liu

Keyword(s):

High Temperature ◽

Shape Memory Alloys ◽

Shape Memory ◽

Two Phase ◽

Shape Memory Properties

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Mechanical and shape memory properties of Ni54Mn25Ga21 high-temperature shape memory alloy

Materials Science and Engineering A ◽

10.1016/j.msea.2006.02.163 ◽

2006 ◽

Vol 438-440 ◽

pp. 978-981 ◽

Cited By ~ 21

Author(s):

Yan Li ◽

Yan Xin ◽

Chengbao Jiang ◽

Huibin Xu

Keyword(s):

High Temperature ◽

Shape Memory Alloy ◽

Shape Memory ◽

Shape Memory Properties

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.654-656.2095 ◽

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.

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