钙热还原制备Sm_(2)Co_(17)合金及磁性能研究  

Preparation of Sm_(2)Co_(17)Alloy by Calciothermic Reduction and Magnetic Properties

作　　者：刘东辉[1] 张小林[1] 牛飞 杨幼明[1,2,3] LIU Donghui;HANG io-lin;NU Fei;YANG You-ming(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China;Jiangxi Provincial Key Laboratory of Flash Green Development and Recycling,Jiangxi University of Science and Technology,Ganzhou 341000,China;National Engineering Research Center for lonic Rare Earth,Ganzhou 341000,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000 [2]江西理工大学江西省闪速绿色开发与循环利用重点实验室,江西赣州341000 [3]离子型稀土资源开发及应用教育部重点实验室,江西赣州341000

出　　处：《稀土》2023年第4期202-213,I0007,共13页Chinese Rare Earths

基　　金：江西省重点研发计划项目(20192BBE50028);江西省离子型稀土资源绿色开发与高值利用国家重点实验室培育计划(20194AFD44003);江西省自然科学基金项目(20202BABL214024)。

摘　　要：钙作为还原剂无法直接还原SmF_(3)制备金属钐。本文以无水SmF_(3)为原料,对钴诱导SmF_(3)钙热还原制备Sm_(2)Co_(17)合金进行了热力学计算与实验研究。通过电感耦合等离子体光谱仪、X射线衍射仪、扫描电子显微镜及能谱仪和X射线光电子能谱仪等测试方法对合金产物的化学组成、结构、形貌、元素分布和化学价态等进行了分析与表征。结果表明:钴诱导SmF_(3)钙热还原制备Sm_(2)Co_(17)合金在热力学上是可行的,还原产物为Sm_(2)Co_(17)合金与CaF_(2)。当SmF_(3)与Ca用量分别为摩尔比1.1与1.2,保温时间30 s时,获得合金产物中钐质量分数为22.98%,与Sm_(2)Co_(17)合金的理论成分几乎相同。铸态合金产物主要由Th_(2)Zn_(17)结构的2∶17相及CaCu_(5)结构的1∶5相组成。结合电负性原理与XPS分析结果研究了制备Sm_(2)Co_(17)合金的钴诱导机理。Sm_(2)Co_(17)合金快淬带的剩余磁化强度为0.47 T,内禀矫顽力为0.45 kA·m^(-1),最大磁能积为5.23 kJ·m^(-3)。与传统混熔工艺相比,此工艺在每生产一吨Sm_(2)Co_(17)合金中,金属钐制备成本节省约40%。该方法制备的钐钴合金可作为烧结稀土钐钴永磁材料的原料。SmF,cannot be directly reduced to metallic samarium by calcium.This work presents a thermodynamic calcu-lation and synthesis of Sm_(2)Co_(17)by cobalt induced SmF_(3)calciothermic reduction.The composition,structure,morphology,ele-ments distribution and chemical valence of Sm_(2)Co_(17)alloy were analyzed and characterized by inductively coupled plasma,X-ray diffraction,scanning electron microscopy,energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy.The results show that it is thermodynamically feasible to fabricate Sm_(2)Co_(17)alloy by cobalt induced SmF_(3)with Sm_(2)Co_(17)alloy and CaF_(2)as the reduction products.Sm_(2)Co_(17)alloy with 22.98%mass fraction of samarium was achieved under the molar ratio of 1.1 and 1.2 of SmF_(3)and Ca,respectively,for a reaction duration of 30 s.It is almost the same as the nominal composition of Sm_(2)Co_(17)alloy.The Sm_(2)Co_(17)as-cast alloy is composed of 2:17 phase with Th_(2)Zn_(17)structure and 1:5 phase with CaCu_(5)structure.The mechanism of cobalt induction in preparing Sm_(2)Co_(17)alloy was analysed based on the XPS results and the elec-tronegativity principle.B_(r),H_(cj)and(BH)_(max)of Sm_(2)Co_(17)melt-spun ribbon are 0.47 T,0.45 kA·m^(-1)and 5.23 kJ·m^(-3),re-spectively.The production cost of samarium of Sm_(2)Co_(17)production per ton can be reduced by about 40%than the traditional method.Sm_(2)Co_(17)alloy prepared by this method can be used as raw material of sintered rare earth permanent SmCo magnet.

关 键 词：氟化钐 Sm_(2)Co_(17) 钙热还原 诱导机理 磁性能 

分 类 号：TM273[一般工业技术—材料科学与工程]