Improved elastocaloric cooling performance in gradient-structured NiTi alloy processed by localized laser surface annealing

Chen, Junyu; Xing, Leilei; Fang, Gang; Lei, Liping; Liu, Wei

doi:10.1016/j.actamat.2021.116741

Cited by 54 publications

(9 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At higher compressive stress (above 150 MPa), ∆T max ad calculated by the indirect method is apparently larger than that form the direct one. could be attributed to the temperature-induced MT in the non-isothermal PFM simulation, i.e., the relatively large temperature increase at high stress could in turn remarkably hinder the austenite-martensite transition and thus lower the temperature [85]. Cheng et al [86] also report the similar phenomena in electrocaloric effect.…”

Section: Indirect Vs Direct Methodsmentioning

confidence: 88%

Thermodynamically consistent non-isothermal phase-field modelling of elastocaloric effect: indirect vs direct method

Tang¹,

Yang²,

Xu³

et al. 2023

Preprint

View full text Add to dashboard Cite

Modelling elastocaloric effect (eCE) is crucial for the design of environmentally friendly and energy-efficient eCE based solid-state cooling devices. Here, a thermodynamically consistent non-isothermal phase-field model (PFM) coupling martensitic transformation with mechanics and heat transfer is developed and applied for simulating eCE. The model is derived from a thermodynamic framework which invokes the microforce theory and Coleman-Noll procedure. To avoid the numerical issue related to the non-differentiable energy barrier function across the transition point, the austenite-martensite transition energy barrier in PFM is constructed as a smooth function of temperature. Both the indirect method using isothermal PFM with Maxwell relations and the direct method using non-isothermal PFM are applied to calculate the elastocaloric properties. The former is capable of calculating both isothermal entropy change and adiabatic temperature change (∆T ad ), but induces high computation cost. The latter is computationally efficient, but only yields ∆T ad . In a model Mn-22Cu alloy, the maximum ∆T ad (∆T max ad ) under a compressive stress of 100 MPa is calculated as 9.5 and 8.5 K in single crystal (3.5 and 3.8 K in polycrystal) from the indirect and direct method, respectively. It is found that the discrepancy of ∆T max ad by indirect and direct method is within 10% at stress less than 150 MPa, confirming the feasibility of both methods in evaluating eCE at low stress. However, at higher stress, ∆T max ad obtained from the indirect method is notably larger than that from the direct one. This is mainly attributed to that in the non-isothermal PFM simulations, the relatively large temperature increase at high stress could in turn hamper the austenite-martensite transition and thus finally yield a lower ∆T ad . The results demonstrate the developed PFM herein, combined with both indirect and direct method for eCE calculations, as a practicable toolkit for the computational design of elastocaloric devices.

show abstract

Section: Indirect Vs Direct Methodsmentioning

confidence: 88%

Thermodynamically consistent non-isothermal phase-field modelling of elastocaloric effect: indirect vs direct method

Tang¹,

Yang²,

Xu³

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…[ 33 ] Besides, a gradient‐structured (GS) Ni–Ti shape memory alloy with average grain sizes ranging from ≈10 to ≈3500 nm by localized laser surface annealing on the severely cold‐rolled substrate can achieve the enhanced elastocaloric cooling performances. [ 54 ] The elastocaloric cooling capacity (Δ T ad ) and efficiency (COP mat ) of the microstructural gradient Ni–Ti shape memory alloy can be improved to be as high as 50% and 130% relative to that of the conventional homogeneous nanocrystalline and coarse‐grained NiTi, respectively. [ 55 ] This verifies that the elastocaloric performance of NiTi alloys could be potentially improved if the gradient structure could be designed.…”

Section: Functionally Graded Ni–ti Shape Memory Alloysmentioning

confidence: 99%

“…[33] Besides, a gradient-structured (GS) Ni-Ti shape memory alloy with average grain sizes ranging from %10 to %3500 nm by localized laser surface annealing on the severely cold-rolled substrate can achieve the enhanced elastocaloric cooling performances. [54] Figure 2. Optical image showing the shape evolution upon cooling and heating of the prestrained compositional gradient Ni-Ti shape memory alloys.…”

Section: Continuous Microstructural Gradient Ni-ti Shape Memory Alloysmentioning

confidence: 99%

Brief Overview of Functionally Graded NiTi‐Based Shape Memory Alloys

et al. 2023

View full text Add to dashboard Cite

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.

show abstract

“…And the results also showed that the DT adi increased gradually with increasing strain rates due to an increasing fraction of materials subjected to stress-induced martensite and a better adiabatic state. 10 The experimental method has been widely adopted and achieved many achievements in the study of the inuence of strain rate on the elastocaloric effect of Ni-Ti-based, [11][12][13] Cubased, 14 Fe-based 15 and Ni-Mn-based alloys. 16 However, limited by the experimental method, the essence of the effect of strain rate on mechanical behavior remains unclear.…”

Section: Introductionmentioning

confidence: 99%

“…As a result, it is difficult to accurately determine the variation trend of the phase transformation stage with increasing strain rates, which leads to deviations in the study of the elastocaloric effect of elastocaloric refrigeration alloys. 2,7,12 Fortunately, the booming development of MD technology has made it possible to study the mechanical behavior at microscopic and atomic scales. [17][18][19] Investigating mechanical behavior through MD simulation can not only easily realize adiabatic conditions, 20 but also study the evolution processes of the parameters at different strain rates dynamically, such as stress, temperature, total kinetic energy, phase content, etc., 21 which overcomes the shortcomings of the experimental methods.…”

Section: Introductionmentioning

confidence: 99%

The essence of the effect of strain rate on the mechanical behavior of the Fe14.6Ni (at%) elastocaloric refrigeration alloy: a molecular dynamics study

Li,

An,

Chen

et al. 2024

Nanoscale Adv.

View full text Add to dashboard Cite

show abstract

Improved elastocaloric cooling performance in gradient-structured NiTi alloy processed by localized laser surface annealing

Cited by 54 publications

References 72 publications

Thermodynamically consistent non-isothermal phase-field modelling of elastocaloric effect: indirect vs direct method

Thermodynamically consistent non-isothermal phase-field modelling of elastocaloric effect: indirect vs direct method

Brief Overview of Functionally Graded NiTi‐Based Shape Memory Alloys

The essence of the effect of strain rate on the mechanical behavior of the Fe14.6Ni (at%) elastocaloric refrigeration alloy: a molecular dynamics study

Contact Info

Product

Resources

About