以低纯度钆研究Gd_5Si_2Ge_2的磁热效应及制备工艺  

Procedure for Preparing Gd_5Si_2Ge_2 from Commercial Gadolinium and Studying Its Magnetocaloric Effect

作　　者：王志强[1] 颜世宏[1] 李宗安[1] 于敦波[1] 陈博雨[1] 赵斌[1] 

机构地区：[1]北京有色金属研究总院有研稀土新材料股份有限公司,北京100088

出　　处：《稀有金属》2007年第2期183-186,共4页Chinese Journal of Rare Metals

摘　　要：以99%级的低纯度金属Gd为原料,采用真空感应炉制备工艺,辅以1470 K热处理工艺,获得了与99.99%级高纯度Gd为原料制备的Gd5Si2Ge2合金相近的磁热效应,5 T外场下最大磁熵变达17.5 J.kg-1.K-1,对比电弧熔炼与感应熔炼两种制备方法,感应熔炼条件下C,N,O杂质含量明显降低,发现了Gd5Si2Ge2合金巨磁熵变与相结构的本质联系。Gd5Si2Ge2 alloys developed by Ames is recgnized and famous for its magneto-caloric performance. But the process of preparing Gd5Si2Ge2 alloys using high purity gadolinium metal（99.99%） just for obtaining the giant magneto-caloric effect results in high cost and limits its industrial application. An induction furnace process was employed to study the magneto-caloric effect of Gd5Si2Ge2 alloys using com-mercial gadolinium（99.4%）. After melting in induction furnace at 1800 ℃ and subsequent heat treating at 1470 K for one hour, its magneto-caloric effect approximated to that of Gd5Si2Ge2 prepared from the high purity Gd. Through comparing the two method, it is brought out the single phase is the essence of giant magnetio-culoric effects.

关 键 词：磁致冷 感应熔炼 巨磁热效应 

分 类 号：TM273[一般工业技术—材料科学与工程]