Enhanced magnetic refrigeration capacity in Ni-Mn-Ga micro-particles
Enhanced magnetic refrigeration capacity in Ni-Mn-Ga micro-particles
复制标题
Ni-Mn-Ga微粒的磁制冷能力增强
DOI：
10.1016/j.matdes.2018.03.062
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发表时间：
2018-06-15
影响因子：
8.4
通讯作者：
Geng, Lin
中科院分区：
文献类型：
--
作者：
Qian, Mingfang;Zhang, Xuexi;Geng, Lin
具有一阶特性的块体磁制冷材料通常具有磁滞损耗和集中的制冷工作温度区间（Δ T-FWHM），这对磁制冷应用是不利的。在这里，我们报告的Ni-Mn-Gammicro-particles的尺寸类似于38.5-45 μ m制造的研磨和随后的应力释放退火（SRA）。研究了SRA颗粒的显微组织、马氏体相变、磁滞损耗和磁热效应，并与块体合金进行了对比。SRA颗粒中的热损耗和磁滞损耗分别与块体合金中的热损耗和磁滞损耗相比显著降低，所述块体合金中的热损耗和磁滞损耗分别与1.3 K和1.9 J/kg的热损耗和磁滞损耗相比显著降低，所述块体合金中的热损耗和磁滞损耗分别与5.5 K和9.7 J/kg的磁滞损耗相比显著降低，这与相邻晶粒对马氏体/奥氏体相界运动的约束的减少有关。由于SRA颗粒的高比表面积和SRA后的残余内应力，SRA颗粒的MT转变温度范围约为26.5 K，高于块体合金的MT转变温度范围约为5.5 K。结果表明，SRA颗粒具有磁结构部分耦合态，具有25 K的宽Δ T-FWHM和117 J/kg的高制冷量（RCnet）。在此基础上，展望了提高磁制冷效率的可能途径。(C)2018爱思唯尔有限公司版权所有
Bulk magnetic refrigerant materials with first-order character usually possess hysteresis losses and concentrated refrigeration working temperature interval (delta T-FWHM), which are detrimental for magnetic refrigeration applications. Here, we report on Ni-Mn-Gamicro-particles with size similar to 38.5-45 mu m fabricated by grinding and subsequent stress relief annealing (SRA). The microstructure, martensite transformation (MT), hysteresis loss and magnetocaloric effect (MCE) of the SRA particles were studied in comparison with the bulk alloy counterpart. The thermal and magnetic hysteresis losses in SRA particles similar to 1.3 K and similar to 1.9 J/kg were significantly reduced compared to those in the bulk alloy similar to 5.5 K and similar to 9.7 J/kg, respectively, which is related to the reduction of neighboring grain constraints on martensite/austenite phase boundary motion. The MT transformation temperature range of the SRA particles similar to 26.5 K was higher than that of the bulk alloy similar to 5.5 K because of the high specific surface area of the particles and the residual internal stress after SRA. A magneto-structural partly-coupled state was attained in the SRA particles, which is responsible for the wide delta T-FWHM similar to 25 K and the high refrigeration capacity (RCnet) similar to 117 J/kg. Based on these results, a possible approach for the high magnetic refrigeration efficiency is expected and discussed. (C) 2018 Elsevier Ltd. All rights reserved.