Chen, J., Wang, W., Zhang, Q., Lei, L., Ramamurty, U., & Fang, G. (2024). Temperature dependence of elastocaloric effect in a microstructurally graded NiTi alloy. Scripta Materialia, 245, 116060. https://doi.org/10.1016/j.scriptamat.2024.116060
Abstract:
The temperature dependence of elastocaloric cooling properties of a NiTi alloy
with a grain size gradient, which was obtained by cold rolling and subsequent laser
surface annealing, was evaluated and compared with those of coarse-grained and asrolled
NiTi. Results show that the adiabatic temperature change (|ΔTad|) and cooling
efficiency of the gradient-structured NiTi are significantly enhanced over a wider
temperature span (Tspan), making it a superior elastocaloric refrigerant candidate.
Detailed analyses show that while the fine grains present in the core reduce the global
martensitic autocatalytic nucleation potency and increase strength to broaden Tspan, the
coarser grains near the surfaces accommodate interlayer deformation to improve
|ΔTad| . The work provides a method for overcoming the trade-off between cooling
capacity and service temperature span of elastocaloric materials.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the Agency for Science, Technology and Research - Structural Metal Alloys Programme
Grant Reference no. : A18B1b0061