【作者】 邱翠榕；

【导师】 汪厚植；

【作者基本信息】 武汉科技大学 ， 材料学， 2006， 硕士

【摘要】 Fe基纳米晶磁性材料具有优异的软磁性能,是一种极具开发潜力的金属功能材料。机械合金化技术有望成为制备纳米晶Fe基磁性材料的有效途径。本文主要对制备Fe-6.5wt%Si合金微粉、制备FeAl合金微粉和制备FeSiAl合金微粉的工艺和微观结构进行了研究。通过X射线衍射（XRD）,扫描电子显微镜（SEM）,X射线能谱分析（EDS）和差热分析（DTA）等多种测试手段,详细研究了振动球磨制备Fe-6.5wt%Si合金微粉的影响因素,研究了不同球磨条件下产物的结构、形貌和相变;详细研究了纳米晶Fe-Al合金薄膜和纳米晶Fe-Si-Al合金薄膜在高能球磨条件下不同球磨时间产物的结构、组织、形貌和元素分布变化情况。研究表明:制备Fe-wt6.5%Si合金微粉,延长球磨时间,增加球料比和减小进料粒度,都可以提高出粉率。Fe-Si（Si wt%=6.5）合金在氩气气氛保护下在振动球磨过程中物相较为稳定,球磨产物为具有亚微米结构的过饱和固溶体。本论文的最佳实验条件为:球磨时间为12h,球料比为10/1,进料粒度为～1mm。Fe_（100-x）Al_x（x=4, 8, 12wt%）混合粉末,球磨20h可以生成具有bcc结构的纳米晶α-Fe （Al）固溶体,颗粒粒径约为1～30μm。粉末组织包含有纳米级的亚结构,形成具有典型层状结构的复合粉末,也形成了具有Fe核的包覆型粉末;继续球磨,合金的粉末和晶粒不断细化,各元素成分分布逐渐均匀化,球磨30h后的晶格畸变达到0.54%;在全成分范围内,Fe-Al系机械合金化无非晶相生成。本论文实验条件下,Al含量越高,粉末粘结得越厉害。（FeSi）_（100-x）Al_x（x=15,20,25at%）混合粉末,球磨10h可以生成具有bcc结构的纳米晶α-Fe （Al,Si）固溶体,颗粒粒径约为1～20μm。粉末组织包含有纳米级的亚结构;继续球磨,合金的粉末和晶粒不断细化,球磨15h后,晶粒度可达30nm。（FeSi）_（100-x）Al_x（x=15, 20,25at%）混合粉末在高能球磨过程中,形成具有典型层状结构的复合粉末包覆薄膜,包覆层各种元素组分分布均匀;随着球磨的继续进行,颗粒表面越来越圆润,颗粒越来越接近球形。在合金化过程中没有非晶相的生成。更多还原

【Abstract】 Fe based nanocrystalline is a kind of attractive functional material, owing to excellent soft magnetic properties. Mechanical alloying （MA） is expected to produce Fe based nanocrystalline with high performance. The mechanical alloying process and microstructure of Fe-6.5wt%Si alloy powder,Fe-Al alloy powder and FeSiAl alloy powder are studied in this paper.The phases, microstructures, morphologies, cross-sections of mechanical alloying powders were analyzed by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy spectrometer （EDS） analysisrespectively. The main results are as follows:Prolonging milling time, increasing CR and decreasing initial particle size can improve producing Fe-wt6.5%Si alloy powder efficiency. Fe-Si alloy has a stable composition, uperstaturated solid solution with the sub-micron structure, during vibrate ball milling in argon. he optimum method in this paper is milling time for 12h,CR for 10/1 and original partical size for～1mm.Nanocrystallineα-Fe （Al） solid solution has created after Fe_（100-x）Al_x（x=4,8,12wt%）mixture powder ball milling for 20h, with the structure of b.c.c , particle size from 1μm to 30μm and nanocrystalline sub-micron structure . Two kinds of Fe-Al powders are obtained in the process, one is a composite powder with a typical laminar structure, and the other is a powder with iron as the inner core.With the more time of ball milling, alloy partical size and grain size becames smaller and smaller and two kind elements of Fe and Al distribute well-proportioned gradually.After ball milling for 30h the distortion of lattice is up to 0.54%. No amorphous phase forms during the mechanical alloying process.Under condition of this paper the more content of Al, the more felt is.Nanocrystallineα-Fe （Si,Al） solid solution has created after（FeSi）_（100-x）Al_x（x=15,20, 25at%） mixture powder ball milling for 10h, with the structure of b.c.c , particle size from 1μm to 20μm and nanocrystalline sub-micron structure . After ball milling for 15h grain size is up to 30nm. Mixture powder is a composite powder with a typical laminar structure.With the more time of ball milling, alloy partical size and grain size became smaller and smaller , every element distribute well-proportioned gradually and the surface of particle becomes smooth ,the shape of particle becomes spheric shape. No amorphous phase forms during the mechanical alloying process.更多还原