High temperature shape memory alloy Ni50.3Ti29.7Hf20torque tube actuators

Benafan, Othmane; Gaydosh, D. J.

doi:10.1088/1361-665x/aa7ef4

Cited by 29 publications

(29 citation statements)

References 48 publications

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“…The temperature spans A f -A s (or M s -M f ) also broaden as a function of the increase in stresses from 100 to 400 MPa. Such behavior is commensurate with the classical ClausiusClapeyron relationship, as has been previously described [9]. It is noted that the tube fractured on loading to 500 MPa and no data was collected for that case.…”

Section: Constant Torque Thermal Cyclingsupporting

confidence: 84%

Constant-torque thermal cycling and two-way shape memory effect in Ni_50.3Ti_29.7Hf₂₀ torque tubes

Benafan

Gaydosh

2018

Smart Mater. Struct.

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Ni-rich Ni 50.3 Ti 29.7 Hf 20 (at.%) high-temperature shape memory alloy (SMA) tubes were thermomechanically cycled under constant torques. Four loading configurations were examined that consisted of a series of ascending stresses (low-to-high stress from 0 to 500 MPa outer fiber shear stress), a series of descending stresses (high-to-low stress from 500 to 0 MPa), and a series of thermal cycles at a constant stress of 500 MPa, all using an upper cycle temperature (UCT) of 300 °C. The last configuration consisted of another series of ascending stress levels using a lesser UCT of 250 °C. It was found that the descending series trial stabilized the material response in fewer cycles than the other loading paths. Similarly, cycling at a constant stress of 500 MPa for approximately 100 cycles reached near stabilization (<0.05% residual strain accumulation). Transformation shear strains were the highest and most stable when cycled from lower-to-higher stresses (ascending series), reaching 5.78% at 400 MPa. Cycling to lesser UCTs of 250 °C (vs. 300 °C) resulted in the highest two-way shape memory effect (TWSME), measuring over 3.25%. This was attributed to the effect of retained martensite and any transformation dislocations that served to stabilize the TWSME at the lower UCT. Results of this study suggest that different training paths might be used, depending on actuator performance requirements, whether the principal need is to maximize transformation strain, maximize the two-way shear strain, or stabilize the response in fewer cycles.

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Section: Constant Torque Thermal Cyclingsupporting

confidence: 84%

Constant-torque thermal cycling and two-way shape memory effect in Ni_50.3Ti_29.7Hf₂₀ torque tubes

Benafan

Gaydosh

2018

Smart Mater. Struct.

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“…In robotics, many studies deal with the behavior of SMA actuators and the influence on the behavior of mechanisms in which they are integrated [28][29][30][31][32][33]. The use of SMA requires usually the agency of at least one SMA element in an antagonism with a springback component [34][35][36] or another SMA component [37][38][39][40][41].…”

Section: Introductionmentioning

confidence: 99%

Finite element analysis of a prestressed mechanism with multi-antagonistic and hysteretic SMA actuation

Boufayed¹,

Chapelle²,

Destrebecq³

et al. 2020

Meccanica

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This paper deals with the specific hysteretic effects of a multi-antagonistic shapememory alloy (SMA) actuation system in which each wire can be thermally activated individually (one or more at a time). A planar system with six SMA wires organized in a ternary rotational symmetry is studied numerically, via finite element calculation software. The objective is to analyze the functional characteristics of such mechanism, whose response during a thermal activation sequence is multi-antagonistic and hysteretic. Important points are highlighted, such as the avoidance of buckling and plasticity, the possibility of locking a configuration without energy input, and the "attraction" effect of any heating step on the following steps. The feasibility of reaching a given target in the workspace is also illustrated. Finally, the analysis shows the necessity to consider these multi-antagonistic and hysteretic aspects of the actuation in the future design and control of such type of mechanisms. The latter could be of interest as hollow shaft rotary actuators with additional (small) translation degrees of freedom in applications requiring long-term and stable positioning at ambient temperature.

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“…Among all aforementioned alloys, NiTiHf has been shown to be both cost-effective and exhibit better thermomechanical stability. In addition, the composition of NiTiHf is pivotally critical since it can significantly affect the performance and functionality of the part [5][6][7][8]. Recently, with the advancement in additive manufacturing (AM) technology, more complex geometries of NiTi-based alloys are fabricated via methods such as selective laser melting (SLM).…”

Section: Introductionmentioning

confidence: 99%

Additively Manufactured NiTi and NiTiHf Alloys: Estimating Service Life in High-Temperature Oxidation

et al. 2020

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In this study, the effect of the addition of Hf on the oxidation behavior of NiTi alloy, which was processed using additive manufacturing and casting, is studied. Thermogravimetric analyses (TGA) were performed at the temperature of 500, 800, and 900 °C to assess the isothermal and dynamic oxidation behavior of the Ni50.4Ti29.6Hf20 at.% alloys for 75 h in dry air. After oxidation, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to analyze the oxide scale formed on the surface of the samples during the high-temperature oxidation. Two stages of oxidation were observed for the NiTiHf samples, an increasing oxidation rate during the early stage of oxidation followed by a lower oxidation rate after approximately 10 h. The isothermal oxidation curves were well matched with a logarithmic rate law in the initial stage and then by parabolic rate law for the next stage. The formation of multi-layered oxide was observed for NiTiHf, which consists of Ti oxide, Hf oxide, and NiTiO3. For the binary alloys, results show that by increasing the temperature, the oxidation rate increased significantly and fitted with parabolic rate law. Activation energy of 175.25 kJ/mol for additively manufactured (AM) NiTi and 60.634 kJ/mol for AM NiTiHf was obtained.

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High temperature shape memory alloy Ni_50.3Ti_29.7Hf₂₀torque tube actuators

Cited by 29 publications

References 48 publications

Constant-torque thermal cycling and two-way shape memory effect in Ni_50.3Ti_29.7Hf₂₀ torque tubes

Constant-torque thermal cycling and two-way shape memory effect in Ni_50.3Ti_29.7Hf₂₀ torque tubes

Finite element analysis of a prestressed mechanism with multi-antagonistic and hysteretic SMA actuation

Additively Manufactured NiTi and NiTiHf Alloys: Estimating Service Life in High-Temperature Oxidation

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High temperature shape memory alloy Ni50.3Ti29.7Hf20torque tube actuators

Cited by 29 publications

References 48 publications

Constant-torque thermal cycling and two-way shape memory effect in Ni50.3Ti29.7Hf20 torque tubes

Constant-torque thermal cycling and two-way shape memory effect in Ni50.3Ti29.7Hf20 torque tubes

Finite element analysis of a prestressed mechanism with multi-antagonistic and hysteretic SMA actuation

Additively Manufactured NiTi and NiTiHf Alloys: Estimating Service Life in High-Temperature Oxidation

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Product

Resources

About

High temperature shape memory alloy Ni_50.3Ti_29.7Hf₂₀torque tube actuators

Constant-torque thermal cycling and two-way shape memory effect in Ni_50.3Ti_29.7Hf₂₀ torque tubes

Constant-torque thermal cycling and two-way shape memory effect in Ni_50.3Ti_29.7Hf₂₀ torque tubes