高温热压法制备La(Fe,Si)_(13)H_(y)系磁制冷材料的磁热性能研究  

Research on the Magnetocaloric Effect of La(Fe,Si)_(13)H_(y)Magnetic Refrigeration Material Prepared by Hot-Pressed Method at High Temperature

作　　者：程娟 黄焦宏[2] 游才印[1] 李波[2] 刘翠兰[2] 郭亚茹[2] Cheng Juan;Huang Jiaohong;You Caiyin;Li Bo;Liu Cuilan;Guo Yaru(Xi’an University of Technology,Xi’an 710048,China;Baotou Research Institute of Rare Earths,Baotou 014030,China)

机构地区：[1]西安理工大学,陕西西安710048 [2]包头稀土研究院,内蒙古包头014030

出　　处：《稀有金属材料与工程》2023年第1期318-322,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52066001);内蒙自然科学基金(2021MS05016);北方稀土项目(BFXT-2021-D-0013)。

摘　　要：La(Fe,Si)_(13)H_(y)系合金是一种极具发展潜力的室温磁制冷材料,但该材料易粉化,如何成型并保持大磁热效应成为了亟需解决的问题。本研究采用中频感应炉熔炼La_(0.8)Ce_(0.2)Fe_(11.51)Mn_(0.19)Si_(1.3)母合金并退火,之后制备成粉末。合金粉末在650,850和1050℃不同温度下热压成型,将热压块体合金加工成薄片后进行饱和氢化。利用X射线衍射仪、扫描电子显微镜、VersLab对样品的相组成、微观结构、磁热性能进行了研究。在1050℃下热压样品的孔隙率最低,最大体积磁熵变最高,达到了144.7 mJ∙cm^(-3)∙K^(-1)。1050℃热压样品氢化后居里温度提高至室温附近,仍保持了一级磁相变的大磁热效应,且没有裂痕产生,保持了完整性。La(Fe,Si)_(13)H_(y)based alloy is regarded as the candidate of the room temperature magnetic refrigeration materials.However,as the poor mechanical property,the hydride is difficult to be used in the magnetic refrigerator.How to prepare the magnetic refrigerant with large magnetocaloric effect is the key problem to be solved.In this study,La_(0.8)Ce_(0.2)Fe_(11.51)Mn_(0.19)Si_(1.3)master alloy was prepared by medium frequency induction furnace and annealed,followed by milling to powder.The alloy podwer was hot pressed at 650,850 and 1050℃.The resulted La_(0.8)Ce_(0.2)Fe_(11.51)Mn_(0.19)Si_(1.3)alloy was cut into plates and then hydrogenated until saturated.The phase constitution,microstructure and magnetocaloric effect of samples were determined by XRD,SEM and VersLab.The porosity is the lowest and the volumetric magnetic entropy change is the alrgest(144.7 mJ∙cm^(-3)∙K^(-1))for the sample hot pressed at 1050℃.The Curie temperature increases to near room temperature and the large magnetocaloric effect of the first order phase transition still maintains for the sample hot pressed at 1050℃after hydrogenation.No cracks on the surface are found on the hydride and integrity is kept.

关 键 词：磁制冷 磁热效应 热压成型 

分 类 号：TB64[一般工业技术—制冷工程]