Intermetallics ( IF 4.4 ) Pub Date : 2021-06-03 , DOI: 10.1016/j.intermet.2021.107255 Muhammad Imran , Xuexi Zhang , Mingfang Qian , Lin Geng
Stable elastocaloric effect (eCE) over multiple stress cycles is an indispensable aspect for the commercialization of elastocaloric refrigeration. Here, we addressed the enhanced functional stability in polycrystalline Ni53.2±0.4Fe19.4±0.2Ga27.4±0.6 dual-phase alloy, where interstitial γ-phase was incorporated via aging precipitation. The intergranular γ-precipitates confirmed the reversible superelastic effects at room temperature (296 K), which is greatly conducive to multiple interphase movement. As a consequence, notable adiabatic temperature change (ΔTad) 6.2 K with a large coefficient of performance (COPmat) 14.5 was achieved under maximum stress 300 MPa. A stable eCE cooling performance (ΔTad 2.6 K) over 500 superelastic cycles with insignificant degradation was found under nominal stress 250 MPa. Consequently, the current work demonstrates that manipulating the microstructure by incorporating the interstitial secondary phase is a promising approach to enhance the mechanical and functional properties of ferromagnetic shape memory alloys (FMSMAs) for solid-state cooling technology.
中文翻译:
提高多晶 Ni-Fe-Ga 双相合金中弹性热效应的工作稳定性
在多个应力循环中稳定的弹性热效应 (eCE) 是弹性热制冷商业化不可或缺的方面。在这里,我们解决了多晶 Ni 53.2±0.4 Fe 19.4±0.2 Ga 27.4±0.6双相合金中增强的功能稳定性,其中间隙 γ 相通过时效析出相结合。晶间γ-沉淀物证实了室温(296 K)下的可逆超弹性效应,极大地有利于多相间运动。因此,显着的绝热温度变化 ( ΔT ad ) 6.2 K 具有大的性能系数 ( COP mat) 14.5 在最大应力 300 MPa 下达到。稳定的 eCE 冷却性能 ( ΔT ad 2.6 K) 超过 500 次超弹性循环,在 250 MPa 的标称应力下发现劣化不明显。因此,目前的工作表明,通过加入间隙次生相来操纵微观结构是一种很有前途的方法,可以增强用于固态冷却技术的铁磁形状记忆合金 (FMSMA) 的机械和功能特性。