添加B对LaFe_(11.5)Si_(1.5)快淬带残余α-Fe相以及磁热效应的影响  

Influences of Boron Addition on Residual α-Fe Phase and Magnetocaloric Effect of LaFe_(11.5)Si_(1.5) Melt-Spun Ribbons

作　　者：谢鲲[1] 刘立强[1] 余丽艳[1] 宋晓平[2] 

机构地区：[1]山东科技大学,山东青岛266510 [2]西安交通大学,陕西西安710049

出　　处：《稀有金属材料与工程》2009年第12期2238-2241,共4页Rare Metal Materials and Engineering

摘　　要：通过微观分析研究添加B对LaFe11．5Si1．5快淬带中a．Fe杂相的影响，并探讨LaFe11．5Si1．5，（x=0．5，0．7，1．0）化合物的磁相变和磁热效应。与LaFe11．5Si1．5比较，加入B后快淬薄带的显微组织显著细化，在较高B含量的快淬薄带中还得到了非晶态结构。经1000℃回火2～10h后，快淬试样均结晶为立方NaZn13型的La（Fe，Si）13化合物结构。含B快淬薄带经过较短时间的热处理就能得到单相结构，而且残留的a．Fe含量显著降低。磁性能测试表明，随着B含量的增大，LaFe11.5Si1.5Bx（x=0．5，0．7，1．0）化合物的居里温度略有升高；当B含量较低时，化合物具有一级磁相变特征并表现出与LaFe11．5Si1．5化合物相同的巨大磁热效应。The influences of boron addition on secondary phase a-Fe in LaFe11.5Si1.5 melt-spun ribbons were investigated by＂SEM, TEM and XRD. The magnetic transition and magnetocaloric effect of LaFe11.5Si1.5Bx compound （x = 0.5, 0.7, and 1.0） were discussed. Compared with LaFe11.5Si1.5, the melt-spun ribbons have much finer microstructure after B addition, and even amorphous structure is obtained when B content is higher. The melt-spun specimens were crystallized into La（Fe,Si）13 compound structure of cubic NaZn13-type after annealing at 1000 % for 2-10 h. The annealing time can be reduced after B atom introduction to get single phase structure and the amount of residual a-Fe is decreased significantly. Magnetic property test show that Curie temperature of the LaFe11.5Si1.5Bx compound （x = 0.5, 0.7, and 1.0） increased slightly with B content increasing; the LaFe11.5Si1.5B0.5, i.e. low-B-content compound, exhibited first-order magnetic transition characteristics and had the same giant magnetocaloric effect with LaFe11.5Si1.5.

关 键 词：NaZn13型金属间化合物 第二相 非晶相 巨磁热效应 

分 类 号：TG132.2[一般工业技术—材料科学与工程] TM271[金属学及工艺—合金]