【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。更多还原

【Abstract】 Gd5Si2Ge2 alloys developed by Ames is recognized 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 commercial 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.更多还原