摘要
通过电弧熔炼的方法制备了La(Fe1-xCox)13-ySiy(x=0.06,0.07;y=1.1,1.2)合金,将铸态合金进行了120h的退火处理,退火温度1373K。用XRD分析了合金的相组成,并用SEM、TEM分析了合金的微观组织结构。用超导量子干涉磁强计和磁热效应直接测量仪研究了合金的磁性能。结果表明,120h热处理合金的主相为NaZn13型结构,呈岛状分布的少量α-Fe杂质相随着替代元素Co、Si含量的增加而减少,元素替代明显促进了合金在热处理过程中NaZn13型主相的生成。合金的居里温度Tc和绝热温差ΔTab随替代元素的增加表现出规律变化。研究表明,通过改变替代元素含量可在退火时间少于一周的情况下得到具有较大制冷能力的室温磁致冷材料。
The as-cast La（Fe1-xCox）13-ySiy alloys with different Co and Si contents were prepared by electric arc melting.The alloys were annealed at 1373 K for 120 h.The phase compositions and the microstructure of these alloys were systematically analyzed by XRD,SEM and TEM.The magnetocaloric properties of the alloys were investigated by superconducting quantum interference device（SQUID） magnetometer and magnetocaloric effect measuring instrument.The results indicate that the main phase of the alloy annealed for 120 h is NaZn13-type phase.The substitution element not only benefits the formation of the NaZn13-type phase and constrains the appearance of the impurity α-Fe phase in the process of heat treatment,but also affects the magnetocaloric properties of the alloys.The fluctuating of Curie temperature Tc and adiabatic temperature change ΔTab with the content variation of substitution element were discussed detailedly in this paper.This work implies that it takes only less than one week to obtain the room temperature magnetic refrigeration materials with larger refrigerating capacity.
出处
《金属功能材料》
CAS
2013年第2期1-6,共6页
Metallic Functional Materials
基金
工业和信息化部稀土开发应用项目(51001085)
关键词
室温磁致冷
NaZn13型结构
相组成
绝热温差
room temperature magnetic refrigeration
NaZn13-type structure
phase composition
adiabatic temperature difference
