佟永丽,郭杰,任增鑫,徐志洁,孙乃坤.高压烧结时间及颗粒尺寸对片状LaFe11.44Si1.56氢化物块体结构及磁热效应的影响[J].稀有金属材料与工程,2018,47(3):954~960.[Tong Yongli,Guo Jie,Ren Zengxin,Xu Zhijie,Sun Naikun.Effect of Particle Size and Sintering Duration on the Structure and Magnetocaloric Effect of Plate-shaped LaFe11.44Si1.56 Hydrides in High-pressure H2 Atmosphere[J].Rare Metal Materials and Engineering,2018,47(3):954~960.]
高压烧结时间及颗粒尺寸对片状LaFe11.44Si1.56氢化物块体结构及磁热效应的影响
投稿时间:2016-01-28  修订日期:2016-05-24
中文关键词:  室温磁制冷  磁热效应  高气压  颗粒尺寸  磁滞
基金项目:国家自然科学基金资助(项目号51261001); 辽宁省自然科学资助(项目号2013020105);沈阳市科学计划项目资助(项目号F13-316-1-39)
中文摘要:
      La(Fe,Si)13氢化物目前被认为是最具有应用前景的室温磁制冷材料之一,对于主动式磁蓄冷制冷机而言,理想的磁制冷工质为平行排列的片状块体。本工作在压强高达40MPa的高压氢气气氛下烧结制备了不同颗粒尺寸的厚度为0.8mm的片状LaFe11.44Si1.56氢化物块体,研究了颗粒尺寸及高压烧结时间对氢化物块体的结构及磁热效应的影响。和母合金相比,烧结样品的α-Fe含量有明显增加,而烧结时间和颗粒尺寸对α-Fe析出没有显著影响。烧结样品的居里温度在室温以上,并且随着颗粒尺寸和烧结时间的增加而稍有增加。同时,与母合金相比,烧结块体中的磁滞显著降低,这可以归因于较小的颗粒尺寸和样品中存在大量的微观孔洞,降低了相变过程中的内应力。与颗粒尺寸为110~150μm的样品相比,颗粒尺寸小于40μm的片状块体在磁熵变几乎保持不变的基础上,磁滞显著降低35%。在0~1.5T的外磁场下其磁熵变和体积磁熵变在345K达到最大值8.5J/kg.K和53mJ/cm3.K。
Effect of Particle Size and Sintering Duration on the Structure and Magnetocaloric Effect of Plate-shaped LaFe11.44Si1.56 Hydrides in High-pressure H2 Atmosphere
英文关键词:room temperature magnetic refrigeration  magnetocaloric effect  high pressure  particle size  magnetic hysteresis
英文摘要:
      La(Fe,Si)13 hydride is regarded as one of the most promising room-temperature magnetic refrigerants. A typical active magnetic refrigerator machine requires thin plate-shaped refrigerants. In this work, plate-shaped LaFe11.44Si1.56 hydrides with different particle sizes were prepared by sintering in a high-pressure H2 atmosphere of 40MPa. Effect of particle size and sintering duration on the structure and magnetocaloric effect was investigated. Compared to the parent alloy, α-Fe contents of the sintered samples are increased and different particle sizes and sintering duration do not remarkably influence the precipitation of α-Fe. Upon increasing of particle size, Curie temperatures of sintered samples slightly increase and are shifted to above room temperature. Hysteresis of plate-shaped LaFe11.44Si1.56 hydrides has been almost eliminated due to the existence of micropores with a large size of distribution and small particle size, which reduces the internal strain during the process of the phase transitions. Compared with the sintered sample with particle size from 110 to 150μm, the hysteresis loss of the sintered sample with particle size smaller than 40μm is decreased by 35%, while the large magnetic-entropy ΔSm maintains. LaFe11.44Si1.56 thin plate-shaped hydride with particle size smaller than 40μm exhibits a large change ΔSm of 8.5J/kg.K(53mJ/cm3.K) for a field change of 1.5T at 345K.
作者单位E-mail
佟永丽 沈阳理工大学 tyl.tongyongli@163.com 
郭杰 沈阳理工大学  
任增鑫 沈阳理工大学  
徐志洁 沈阳理工大学  
孙乃坤 沈阳理工大学 naikunsun@163.com 
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