Phase transition and mechanical damping properties: A DMTA study of NiTiCu shape memory alloys

Nespoli, Adelaide; Passaretti, Francesca; Villa, Elena

doi:10.1016/j.intermet.2012.09.005

Cited by 49 publications

(28 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…5a. Similar DMA results have been reported in literature for NiTi SMAs [57][58][59][60][61]. The phase transformation processes, which occur during cooling and heating, also manifest themselves through changes in the damping behavior.…”

Section: Dynamic Mechanical Analysissupporting

confidence: 89%

“…The tan d curves in the lower part of Fig. 11 (gray lines) show that the transformation from austenite to martensite is associated with a significant increase in tan d. This increase of damping capacity is related to time-dependent twin boundary motion as suggested in literature [57][58][59][60][61]. On heating from -150°C, tan d decreases at temperatures close to 110°C due to the reverse transformation.…”

Section: Dynamic Mechanical Analysismentioning

confidence: 62%

“…In 5 K intervals, the storage modulus E 0 , loss modulus E 00 , and damping factor tan d were determined. The test parameters were chosen following the DMA standard as outlined in EN ISO 6721-1 [56] and as recommended in previous literature on DMA assessments of SMAs [57][58][59][60][61]. …”

Section: Mechanical Analysismentioning

confidence: 99%

See 2 more Smart Citations

Twinning-Induced Elasticity in NiTi Shape Memory Alloys

Birk

Biswas

Frenzel

et al. 2016

Shap. Mem. Superelasticity

View full text Add to dashboard Cite

Pseudoelasticity (PE) in shape memory alloys relies on the formation of stress-induced martensite during loading and on the reverse transformation during unloading. PE yields reversible strains of up to 8 % and is applied in applications such as medical implants, flexible eye glass frames, damping elements, and others. Unfortunately, PE shows a strong temperature dependence and thus can only be exploited within a relatively narrow temperature window. The present work focuses on a related process, which we refer to as twinning-induced elasticity (TIE). It involves the growth and shrinkage of martensite variants which are stabilized by dislocations, which are introduced by appropriate cold work. TIE yields reversible strains of the order of 3 %. The TIE effect does not suffer from the strong temperature dependence of PE. The weak temperature dependence of mechanical TIE properties makes TIE attractive for applications where temperature fluctuations are large. In the present work, we study the TIE effect focusing on Ni 50 Ti 50 shape memory alloy wires. The degree of plastic pre-deformation of the initial material represents a key parameter of the ingot metallurgy processing route. It governs the exploitable recoverable strain, the apparent Young's modulus, and the widths of the mechanical hysteresis. Dynamic mechanical analysis is used to study the effects of pre-deformation on elementary microstructural processes which govern TIE.

show abstract

Section: Dynamic Mechanical Analysissupporting

confidence: 89%

Section: Dynamic Mechanical Analysismentioning

confidence: 62%

See 1 more Smart Citation

Twinning-Induced Elasticity in NiTi Shape Memory Alloys

Birk

Biswas

Frenzel

et al. 2016

Shap. Mem. Superelasticity

View full text Add to dashboard Cite

show abstract

“…With a view to widening the application of NiTi SMA in the domain of engineering, third elements are added to the binary NiTi SMA in order to change the transformation temperature or hysteresis [2][3][4][5][6]. For example, Cu element is added to binary NiTi SMA so as to significantly lower the phase transformation hysteresis, which lays the foundation for the application of an actuator or micro-electro-mechanical system (MEMS) [7,8].…”

Section: Introductionmentioning

confidence: 99%

Deformation Behavior and Microstructure Evolution of NiTiCu Shape Memory Alloy Subjected to Plastic Deformation at High Temperatures

Jiang

Sun

Zhang

et al. 2017

Metals

View full text Add to dashboard Cite

Deformation behavior and microstructure evolution of NiTiCu shape memory alloy (SMA), which possesses martensite phase at room temperature, were investigated based on a uniaxial compression test at the temperatures of 700~1000 • C and at the strain rates of 0.0005~0.5 s −1 . The constitutive equation of NiTiCu SMA was established in order to describe the flow characteristic of NiTiCu SMA, which is dominated by dynamic recovery and dynamic recrystallization. Dislocations become the dominant substructures of martensite phase in NiTiCu SMA compressed at 700 • C. Martensite twins are dominant in NiTiCu SMA compressed at 800 and 900 • C. Martensite twins are not observed in NiTiCu SMA compressed at 1000 • C. The microstructures resulting from dynamic recovery or dynamic recrystallization significantly influences the substructures in the martensite phase of NiTiCu SMA at room temperature. Dislocation substructures formed during dynamic recovery, such as dislocation cells and subgrain boundaries, can suppress the formation of twins in the martensite laths of NiTiCu SMA. The size of dynamic recrystallized grains affects the formation of martensite twins. Martensite twins are not easily formed in the larger recrystallized grain, since the constraint of the grain boundaries plays a weak role. However, in the smaller recrystallized grain, martensite twins are induced to accommodate the transformation from austenite to martensite.

show abstract

“…In this paper, DSC was also used to have information about the chemical composition and the thermo-mechanical history of all the samples. In order to assess the chemical composition of each specimen, we focused on some studies elsewhere reported [29,30] and on some DSC observations of several NiTi samples (with Ni content between 50 and 51 at.%) that were prepared as reference in our laboratory, see Fig. 2.…”

Section: Introductionmentioning

confidence: 99%

DSC and three-point bending test for the study of the thermo-mechanical history of NiTi and NiTi-based orthodontic archwires

Nespoli

Villa

Bergo

et al. 2015

J Therm Anal Calorim

Self Cite

View full text Add to dashboard Cite

It is a known fact that the NiTi orthodontic archwire is one of the first and most diffuse biomedical applications of shape memory alloys. In the last years, none deep study about orthodontic archwires has been conducted from the material point of view. In general, the clinical response is the principal aspect that has been investigated for this application. Nonetheless, the accurate mechanical and physical characterization of the archwires can be very important to add new developments to this biomedical product and to give a substantial contribution to the indispensable evolution that is crucial for better clinic results. In fact, the principal aspect that it is needed for further improvements is the study of the optimal force that does not cause damage to the surrounding tissues. According to this statement, a deep study about the thermomechanical characterization of several pseudoelastic commercial archwires used in the straight-wire low-friction techniques is presented. In detail, flexural mechanical tests in the three-point-bending configuration were conducted to assess the archwires unloading force, while differential scanning calorimetry was used to study the phase transition temperatures, and the thermo-mechanical history of each specimen. Both NiTi and NiTiCu commercial archwires were tested, and different geometries were considered. For all the archwires, an excellent repeatability of the results has been found. This series of characterizations provides a complete view of the thermo-mechanical properties of the material, and therefore it shows the possibility to modulate the functional properties developed by the device as a function of the biological field.

show abstract

Phase transition and mechanical damping properties: A DMTA study of NiTiCu shape memory alloys

Cited by 49 publications

References 35 publications

Twinning-Induced Elasticity in NiTi Shape Memory Alloys

Twinning-Induced Elasticity in NiTi Shape Memory Alloys

Deformation Behavior and Microstructure Evolution of NiTiCu Shape Memory Alloy Subjected to Plastic Deformation at High Temperatures

DSC and three-point bending test for the study of the thermo-mechanical history of NiTi and NiTi-based orthodontic archwires

Contact Info

Product

Resources

About