Giant mechanical energy storage capacity and long-term mechanical cyclability in a fine-grained Heusler-type Co51V33Ga16 shape memory alloy

Acta Materialia, Journal Year: 2024, Volume and Issue: 277, P. 120185 - 120185

Published: July 14, 2024

Language: Английский

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Temperature-dependent lattice dynamics study on phase stability, martensitic transformation mechanism, and vibrational entropy properties of B2-type Ni–Mn–Ti Heusler alloy

Journal of Materials Research and Technology, Journal Year: 2024, Volume and Issue: 32, P. 2857 - 2866

Published: Aug. 23, 2024

The all-d-metal Ni–Mn–Ti Heusler alloy with its good mechanical properties and colossal caloric effects has attracted significant attention for mechanocaloric refrigeration. However, the phase stability of B2-type disordered structure at finite temperatures physical origin large transformation entropy change in theoretical calculation remain unclear. In view thermal strongly anharmonic effects, we combined first-principles temperature dependent effective potential calculations to systematically study stability, martensitic mechanism, vibrational B2 partial structures Ni8Mn5Ti3 Ni8Mn6Ti2. Our results showed austenitic Ni8Mn6Ti2 both exhibit antiferromagnetic interaction behaviors targeted temperatures, resolving contradiction between previous experiments. By analysis phonon dispersion relations Helmholtz free energies low high provided a deeper explanation underlying mechanism transformation. Meanwhile, changes were accurately predicted compared experiment results. Specifically, demonstrated that material originates from contributions tetragonal distortion ratio volume change, which provides important guidance great practical significance designing solid-state application

Language: Английский

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Giant Elastocaloric Effect and Improved Cyclic Stability in a Directionally Solidified (Ni50Mn31Ti19)99B1 Alloy

Materials, Journal Year: 2024, Volume and Issue: 17(19), P. 4756 - 4756

Published: Sept. 27, 2024

Superelastic shape memory alloys with an integration of large elastocaloric response and good cyclability are crucially demanded for the advancement solid-state cooling technology. In this study, we demonstrate a giant effect improved cyclic stability in <001>A textured polycrystalline (Ni50Mn31Ti19)99B1 alloy developed through directional solidification. It is shown that adiabatic temperature variation (|ΔTad|) values more than 15 K obtained across range from 283 to 373 K. particular, ΔTad up −27.2 achieved by unloading relatively low compressive stress 412 MPa at 303 Moreover, persistent |ΔTad| exceeding 8.5 sustained over 12,000 cycles, exhibiting very attenuation behavior rate 7.5 × 10−5 per cycle. The enhanced properties observed present ascribed microstructure texturing as well introduction secondary phase due boron alloying.

Language: Английский

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Formation of a-b twin induced by tension in Ni-Mn-Ga magnetic shape memory alloys

Materials Characterization, Journal Year: 2024, Volume and Issue: 209, P. 113710 - 113710

Published: Jan. 29, 2024

Language: Английский

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Phase transition and internal friction behaviors in Mn-doped Co-V-Ga shape memory alloys

Applied Materials Today, Journal Year: 2024, Volume and Issue: 40, P. 102426 - 102426

Published: Sept. 11, 2024

Language: Английский

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A point of view of the elastocaloric effect associated with 7M and 5M modulated martensite in Ni–Mn–Ga alloys

Applied Physics Letters, Journal Year: 2024, Volume and Issue: 125(18)

Published: Oct. 28, 2024

Solid-state refrigeration has emerged as the most promising alternative to conventional technology. However, for this technology be applicable, caloric effects produced in alloys must highly reversible. In context, we compare elastocaloric effect of two Ni–Mn–Ga with different types modulated martensite. The effect, quantified isothermal entropy change (ΔSela), was investigated Ni50Mn28Ga22 and Ni50Mn30Ga20 5M 7M martensite, respectively. Maximum ΔSela values obtained were 1.91 J kg−1 K−1 during cooling 1.83 heating martensite 0.19 0.26 7M, a constant applied stress 10 MPa. although exhibited lower ΔSela, its reversibility higher. Therefore, our results could useful selecting good material used solid-state refrigeration.

Language: Английский

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Large room-temperature elastocaloric effect and enhanced specific adiabatic temperature change of Ni–Mn-based shape memory microwire

Applied Physics Letters, Journal Year: 2024, Volume and Issue: 125(22)

Published: Nov. 25, 2024

Continuous miniaturization of electronic components puts higher demands on the heat dissipation micro-systems, which requires environmental friendliness, good exchange capability, and high-performance micro-refrigeration materials. Here, we developed a Ni–Mn–Fe–In microwire fabricated by Taylor–Ulitovsky method, showing ⟨001⟩A orientation close to axial direction microwire. Due large volume change ΔV/V (−1.24%), entropy ΔStr 43.6 J kg−1 K−1 was achieved in Owing low driving force with single crystalline microwire, adiabatic temperature −5.7 K at room after removing stress 120 MPa. Thus, high specific 47.5 K/GPa obtained is highest value among all reported low-dimension elastocaloric materials, including thin films/foils, microwires/wires, ribbons. The outstanding comprehensive properties give this great application potential compactness refrigeration devices.

Language: Английский

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Multi-Step Phase-Transformation of Ni-Mn-Ga Smart Microwires Under Stress- and Strain-Controlled Tensile Modes

Published: Jan. 1, 2024

Language: Английский

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