Effects of nanoprecipitation on the shape memory and material properties of an Ni-rich NiTiHf high temperature shape memory alloy

Karaca, H.E.; Saghaian, Sayed M.; Ded, G.S.; Tobe, Hirobumi; Başaran, B.; Maier, Hans Jürgen; Noebe, Ronald D.; Chumlyakov, Yu. I.

doi:10.1016/j.actamat.2013.08.048

Cited by 231 publications

(123 citation statements)

References 33 publications

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“…For actuation in a medium temperature range of about 100-400 ○ C, mainly Ni-Ti based ternary (Ni-Ti-X) systems have been proposed. [8][9][10] These alloys show promising shape memory characteristics, i.e. actuation strain and microstructural stability, but at the same time suffer from two main drawbacks, i.e.…”

mentioning

confidence: 99%

On the functional degradation of binary titanium–tantalum high-temperature shape memory alloys — A new concept for fatigue life extension

Niendorf

Krooß

Batyrsina

et al. 2014

Funct. Mater. Lett.

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High-temperature shape memory alloys are promising candidates for actuator applications at elevated temperatures. Ternary nickeltitanium-based alloys either contain noble metals which are very expensive, or suffer from poor workability. Titanium-tantalum shape memory alloys represent a promising alternative if one can avoid the cyclic degradation due to the formation of the omega phase. The current study investigates the functional fatigue behavior of Ti-Ta and introduces a new concept providing for pronounced fatigue life extension.Keywords: Omega phase; martensite; phase transformation; microstructure; shape memory effect.Conventional shape memory alloys (SMAs) have been intensely investigated over the last decades due to their extraordinary properties. 1-6 Different metallic alloys can show a shape memory effect, e.g. Cu-based 5 and Fe-based systems, 6 but Ni-Ti is still the most widely used conventional SMA 3 due to good functional and structural properties. Unfortunately, the transformation temperatures of Ni-Ti are limited to below 100 ○ C, thus hindering applications in elevated and high-temperature regimes. 7 As shape memory actuators allow for designing devices characterized by high compactness and efficiency, a large effort has been spent to develop high-temperature shape memory alloys (HTSMAs). For actuation in a medium temperature range of about 100-400 ○ C, mainly Ni-Ti based ternary (Ni-Ti-X) systems have been proposed. [8][9][10] These alloys show promising shape memory characteristics, i.e. actuation strain and microstructural stability, but at the same time suffer from two main drawbacks, i.e. poor workability and/or high amounts of noble metals. 8,9,11 Titanium-tantalum SMAs represent a promising alternative to overcome all these issues if one can avoid the cyclic degradation due to the formation of the !-phase. The current study investigates the functional fatigue behavior of Ti-Ta and introduces a new concept providing pronounced fatigue life extension. The cyclic deformation behavior of a polycrystalline titanium-tantalum (Ti-Ta) alloy containing 30 at.% Ta under iso-stress loading during thermal cycling employing temperatures ranging from 50 ○ C to 600 ○ C was investigated. In order to reveal the most detrimental factor leading to a change of transformation temperatures and a loss of transformation strain, fatigue tests were conducted with differing heating and cooling rates and aging treatments. Using X-ray diffraction (XRD) it could be clearly shown that stabilization of the high-temperature parent phase (β-phase) and the concomitant evolution of the !-phase led to functional degradation. The results of the current study suggest that both phases are mainly induced through aging during high temperature exposure and not by martensitic transformation events during cycling. A new concept employing single-step short-time annealing for regeneration of the initial transformation behavior is introduced.As shown and intensively discussed in a series of studies published by Buenconsejio et al.,[12]...

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mentioning

confidence: 99%

On the functional degradation of binary titanium–tantalum high-temperature shape memory alloys — A new concept for fatigue life extension

Niendorf

Krooß

Batyrsina

et al. 2014

Funct. Mater. Lett.

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“…The NiTi-based SMAs, especially the commercially available Ni 49. 9 Ti 50.1 (at.%), have proved to be viable materials for the design of solid-state actuator systems. Their ability to produce large recoverable work output at a lower cost is a major reason for their popularity ( Ref 5,6).…”

Section: Introductionmentioning

confidence: 99%

“…Many efforts have been made to overcome these undesirable limitations in the Ni 49. 9 Ti 50.1 , including the development of several alternative training procedures and addition of other alloys. For instance, thermal cycling and different aging treatments ( Ref 7) have been proved to influence the dimensional stability and transformation temperature of this material system.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 Tube Actuators

Owusu-Danquah

Saleeb

Dhakal

et al. 2015

J. of Materi Eng and Perform

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A shape memory alloy (SMA) actuator typically has to operate for a large number of thermomechanical cycles due to its application requirements. Therefore, it is necessary to understand the cyclic behavioral response of the SMA actuation material and the devices into which they are incorporated under extended cycling conditions. The present work is focused on the nature of the cyclic, evolutionary behavior of two widely used SMA actuator material systems: (1) a commercially available Ni 49.9 Ti 50.1 , and (2) a developmental high-temperature Ni 50.3 Ti 29.7 Hf 20 alloy. Using a recently developed general SMA modeling framework that utilizes multiple inelastic mechanisms, differences and similarities between the two classes of materials are studied, accounting for extended number of thermal cycles under a constant applied tensile/compressive force and under constant applied torque loading. From the detailed results of the simulations, there were significant qualitative differences in the evolution of deformation responses for the two different materials. In particular, the Ni 49.9 Ti 50.1 tube showed significant evolution of the deformation response, whereas the Ni 50.3 Ti 29.7 Hf 20 tube stabilized quickly. Moreover, there were significant differences in the tension-compression-shear asymmetry properties in the two materials. More specifically, the Ni 50.3-Ti 29.7 Hf 20 tube exhibited much higher asymmetry effects, especially at low stress levels, compared to the Ni 49.9 Ti 50.1 . For both SMA tubes, the evolution of the deformation response under thermal cycling typically exhibited regions of initial transients, and subsequent evolution.

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“…8b. Their ability to show superelasticity at temperatures near or above 100°C makes them promising high-temperature shape memory alloys and alternatives to NiTiHf alloys [29,33]. Thermal experiments revealed that transformation temperatures are highly dependent on B content in CuAlMnB alloys.…”

Section: Resultsmentioning

confidence: 97%

The effects of substituting B for Cu on the magnetic and shape memory properties of CuAlMnB alloys

et al. 2016

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The effects of B addition on the magnetization, mechanical and shape memory properties in Cu 70-x Al 24-Mn 6 B x at.% (x = 0, 1, 2, 3, 4) alloys have been investigated. The ductility was decreased, while the strength was improved with B addition. Transformation temperatures were increased with B content due to increased e/a ratio. Martensite start temperature of B-free CuAlMn was found to be 37.3°C and increased to 218.8°C with 4 % B addition. B-free CuAlMn exhibited shape memory effect with a recoverable strain of 2.25 % under 200 MPa and a perfect superelasticity with a recoverable strain of 2.5 % at 163°C. B addition degraded the shape memory properties and eventually resulted in the lack of recoverable strain. In addition, saturation magnetization was increased with B content. Moreover, the addition of B slightly decreased the ductility of the alloy. It was found that the magnetization, mechanical and shape memory properties CuAlMn alloys can be tailored by quaternary alloying with B.

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Effects of nanoprecipitation on the shape memory and material properties of an Ni-rich NiTiHf high temperature shape memory alloy

Cited by 231 publications

References 33 publications

On the functional degradation of binary titanium–tantalum high-temperature shape memory alloys — A new concept for fatigue life extension

On the functional degradation of binary titanium–tantalum high-temperature shape memory alloys — A new concept for fatigue life extension

A Comparative Study of Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 Tube Actuators

The effects of substituting B for Cu on the magnetic and shape memory properties of CuAlMnB alloys

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