烧结La(FeCoSi)13BX合金磁热效应机理的研究

项目名称： 烧结La(FeCoSi)13BX合金磁热效应机理的研究

项目编号： No.50861001

项目类型： 地区科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 黄焦宏

作者单位： 包头稀土研究院

项目金额： 28万元

中文摘要： 本项目采用粉末冶金烧结及SPS方法制备了La(FeCoSi)13BX合金，研究了粉末粒度、热处理时间、压力等对合金磁热效应的影响。并且通过添加微量元素研究了其合金的磁热效应、磁滞、热滞、合金的稳定性能及合金在磁制冷机上的制冷效果等。 采用工业纯原料用粉末冶金方法通过冶炼中间合金-制粉-压型（初压-等静压）-烧结-均匀化热处理的工艺和SPS烧结方法分别制备了La(Fe11.2Co0.7Si1.1)B0.25样品。样品呈现典型的三相：主相、富La相和?-Fe相，这与铸态合金是一致的。粒度对于磁热效应的影响随着热处理时间的长短而不同，对于短时间热处理（1h），粉末粒度越小，磁热效应越高；而对于长时间处理（20h），粒度对磁热效应的影响不是特别明显。成型压力对磁热效应有较大的影响，压力越大，磁热效应越大。 粉末成型烧结和SPS烧结均能有效地拓宽磁热效应峰值的温度范围，有助于该材料在较宽的温度范围内使用。在LaFe11.2Co0.7Si1.1合金中调价微量的B、Ni、V、Cr、Ti等元素能够有效地调节该合金的磁相变点。拓宽了合金的使用温度。

中文关键词： La(FeCoSi)13BX;磁热效应;粉末;机理

英文摘要： In the present work, La(FeCoSi)13BX alloys were prepared by powder metallurgy method and SPS method. The influence of granularity, heat treatment time and pressure etc on magnetocaloric effect was studied. The magnetocalric effect, magnetic hysteresis, heat hysteresis, stability and performance on magnetic refrigerator of alloys adding microelements were studied. The La(Fe11.2Co0.7Si1.1)B0.25 samples was prepared with industrial purity raw materials by metallurgy method and SPS method, respectively. The sample is composed of three phases: main phase, La-rich phase and Fe-rich phase. It is as same as the status of sample in cast. The infuluence of granularity on magnetocaloric effect is depended on heat treatment time. A smaller granularity means higher magnetocaloric effect, when the heat treatment time(1h) is short. But the influence of granularity was not obvious, when the heat treatment time(20h) is long. The influence of pressure on magnetocaloric effect is large. A larger pressure means larger magnetocalric effect. The magnetocaloric effect peak value temperature range could be expanded by both powder metallurgy method and SPS method. Thus, the materials prepared by the two method could be used in wide temperature range. The magnetic phase transition temperature of LaFe11.2Co0.7Si1.1 alloy could be adjusted by adding microelements such as B, Ni, V, Cr, Ti etc effectively. It also expanded the using temperature range of alloy.

英文关键词： La(FeCoSi)13BX; magnetocaloric effect; powder; mechanism