作　　者： ; ; ; ; ; ; ;

机构地区： 四川大学

出　　处： 《稀有金属材料与工程》 2009年第5期887-890,共4页

摘　　要： 采用XRD、SEM及EDS等手段研究了LaFe13-xSix(x=1.43,1.56,2.4)合金铸态及高温短时退火后的结构与显微组织,并通过振动样品磁强计研究了退火态合金的磁性能。结果表明:铸态LaFe11.57Si1.43和LaFe11.44Si1.56含有大量的α-Fe和LaFeSi相,显微组织呈典型的树枝晶状,LaFe11.44Si1.56还含有较多具有NaZn13型结构的相。铸态LaFe10.6Si2.4可直接得到具有NaZn13型结构的主相,组织呈胞状。在1350℃退火0.5h并随炉冷却后,除含有少量α-Fe及LaFeSi杂相外,LaFe11.57Si1.43和LaFe11.44Si1.56主要以具有NaZn13型结构的相为主,其组织呈等轴晶状。磁性测量结果表明:随Si含量的增加,合金居里温度逐渐升高。 The microstructures of the as-cast and the shortly annealed LaFe13-xSix （x=1.43, 1.56, 2.4） alloys at high temperature were investigated by X-ray diffraction, scanning electron microscope and energy dispersive spectroscopy. It was demonstrated that the microstructure of the as-cast LaFe11.57Si1.43 was characterized by dendrite grains, which contained a large amount of a-Fe and LaFeSi. LaFe11.44Si1.56 had not only dendrite grains but also more amount of phases crystallized in NaZn13-type structure besides a-Fe and LaFeSi. The NaZn13-type structure of the as-cast LaFe10.6Si2.4 could be directly obtained and characterized by cellular grains. After annealing at 1350 ℃ for half an hour, the dendrite grains were turned into equiaxed ones, and NaZn13-type structure phases were formed as the matrix phase, with the existence of α-Fe and impurity phase LaFeSi.

关 键 词： 高温退火 型结构 显微组织 磁制冷材料

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]