Microstructural study and simulation of intrinsic two-way shape memory behavior of functionally graded Ni-rich/NiTiCu thin film

Mohri, Maryam; Taghizadeh, Milad; Wang, Di; Hahn, Horst; Nili‐Ahmadabadi, Mahmoud

doi:10.1016/j.matchar.2017.11.056

Cited by 15 publications

(13 citation statements)

References 40 publications

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“…The R-phase was identified, as it can be seen in Fig. 2 [15,22,23]. However, the R-phase peak splitting is not well defined, as it is exemplified in Fig.…”

Section: Resultsmentioning

confidence: 97%

Effect of the initial phase constitution in the low-cycle fatigue of NiTi wires

Silva

Buono

2019

SN Appl. Sci.

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Vastly used due to their functional properties, NiTi shape memory alloys have mechanical properties and fatigue resistance known to be strongly affected by their thermomechanical state. In this work, the goal was to evaluate the fatigue resistance of near equiatomic Ni-rich NiTi heat treated wires in different tests temperature. In this manner, it was possible to evaluate the phase constitution effect on the fatigue resistance with a fixed thermomechanical condition. For that, a heat treatment at 500 °C for 30 min was performed in initially superelastic wires in an argon atmosphere. DSC tests were performed in order to obtain the transformation temperatures and there different fatigue test temperatures were chosen according to the phase stability ranges. Rotating-bending fatigue tests took place in proper equipment at 4% maximum strain, evaluating the properties of structures constituted by the R-phase, austenite and R-phase + austenite, in each selected test temperature. The results showed that the R-phase presents higher low-cycle fatigue resistance than austenite and a fatigue mechanism was proposed.

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“…The R-phase was identified, as it can be seen in Fig. 2 [15,22,23]. However, the R-phase peak splitting is not well defined, as it is exemplified in Fig.…”

Section: Resultsmentioning

confidence: 97%

Effect of the initial phase constitution in the low-cycle fatigue of NiTi wires

Silva

Buono

2019

SN Appl. Sci.

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“…The compositional gradient Ni-Ti shape memory alloys can be achieved through diffusion annealing, [16,20] powder metallurgy, [21][22][23] magnetron sputtering, [24][25][26][27][28] additive manufacturing, etc. [29,30] For instance, a thin layer of Ni (TiN) can be prepared at the surface of the atomic Ni-Ti thin plate using magnetron sputtering or vapor deposition.…”

Section: Compositional Gradient Ni-ti Shape Memory Alloysmentioning

confidence: 99%

“…[20] Two-stage B19´⇌ R ⇌ B2 and two-way shape memory effect can be found in compositional gradient Ti-Ni bilayer thin films. [27,28] Besides, the peculiar martensitic transformation in compositional gradient Ni-Ti shape memory alloys also promotes to the superior mechanical and functional properties. On the one hand, the stress-strain curves of shape memory alloys with a compositional gradient are featured with multiple-stage stress plateau corresponding to the stress-induced martensitic transformation.…”

Section: Compositional Gradient Ni-ti Shape Memory Alloysmentioning

confidence: 99%

Brief Overview of Functionally Graded NiTi‐Based Shape Memory Alloys

et al. 2023

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Shape memory alloys (SMAs) are kinds of smart materials that have superior properties such as shape memory effect and superelasticity, which have the most potential applications in various fields, especially in aerospace, naval, automobile and biomedicine industries, etc. Nevertheless, the inherent natures of shape memory alloys are characterized by the smaller transformation temperature intervals and transformation stress intervals, which make the devices have poor control ability. To achieve the accurate controllability for progressive movement, creating functionally graded shape memory alloys has been adopted. Herein, the classification, fabrications, microstructural features, and performances of functionally graded shape memory alloys are reviewed. For comparison, the creation of various gradients in shape memory alloys can widen the transformation temperature intervals and transformation stress intervals to some extent. In addition, the formation of the compositional, microstructural, or geometrical gradient also contributes to the generation of excellent performances such as the four‐way shape memory effect, higher strength, and larger temperature window for the stress‐assisted two‐way shape memory effect, etc. Such superior functions promote a wider application range of shape memory alloys.

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“…As a functional material with shape memory effect (SME), shape memory alloys (SMAs) has been widely used in the engineering field [1]. NiTi-based SMAs and Fe-based SMAs are the two most mature ones at present [2][3][4][5][6][7]. SMA tube coupling is the most successful example of SMA for engineering applications, which are mainly used in pipeline joints in aerospace, petrochemical and nuclear industries [8].…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of extrusion of FeMnSiCrNi/NiTiNb dissimilar shape memory alloy composite tube based on finite element method and cellular automaton

Jiang

Sun

2022

IOP Conf. Ser.: Mater. Sci. Eng.

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FeMnSiCrNi/NiTiNb dissimilar shape memory alloy composite tube is firstly put forward and it can be fabricated by means of isothermal extrusion. Based on Arrhenius constitutive model of FeMnSiCrNi and NiTiNb shape memory alloys, isothermal extrusion of FeMnSiCrNi/NiTiNb dissimilar shape memory alloy composite tube is simulated by rigid viscoplastic finite element method. It can be found that the deformation zone of the dissimilar shape memory alloy composite tube is always in a three-dimensional compressive stress state during extrusion, and the deformation of the inner tube is obviously higher than that of the outer tube. It is necessary to guarantee the interface compatibility between the inner tube and the outer tube during isothermal extrusion of FeMnSiCrNi/NiTiNb dissimilar shape memory alloy composite tube. The relationship between macroscopic process variables and microscopic variables during plastic deformation of FeMnSiCrNi shape memory alloy tube at high temperature is established by coupling finite element simulation and cellular automaton simulation. The microstructural evolution of FeMnSiCrNi shape memory alloy in different deformation zones during isothermal extrusion of dissimilar shape memory alloy composite tube is simulated. It can be concluded that the grain size of dynamic recrystallization is reduced with the increase of plastic strain in the deformation zone.

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Microstructural study and simulation of intrinsic two-way shape memory behavior of functionally graded Ni-rich/NiTiCu thin film

Cited by 15 publications

References 40 publications

Effect of the initial phase constitution in the low-cycle fatigue of NiTi wires

Effect of the initial phase constitution in the low-cycle fatigue of NiTi wires

Brief Overview of Functionally Graded NiTi‐Based Shape Memory Alloys

Numerical simulation of extrusion of FeMnSiCrNi/NiTiNb dissimilar shape memory alloy composite tube based on finite element method and cellular automaton

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