搅拌球磨制备纳米晶复相永磁粉末的微观组织和磁性能研究  

Microstructure and Magnetic Properties of Nanocomposite Nd_2Fe_(14)B/α-Fe Permanent Magnetic Powder Prepared by Mechanical Milling

作　　者：王迎[1] 王尔德[1] 

机构地区：[1]哈尔滨工业大学,黑龙江哈尔滨150001

出　　处：《稀有金属材料与工程》2007年第9期1665-1667,共3页Rare Metal Materials and Engineering

摘　　要：采用搅拌球磨法制备了纳米复相Nd2Fe14B/α-Fe永磁合金。借助X射线衍射(XRD)、差示扫描量热法(DSC)、透射电子显微镜(TEM)等分析方法研究了不同球磨时间及晶化处理温度对合金微观组织和磁性能的影响规律。结果表明:随球磨时间的延长,Nd2Fe14B相及α-Fe相的晶粒尺寸迅速减小,球磨5h后粉末由非晶相和晶粒尺寸约为10nm的α-Fe相组成,当晶化处理温度为650℃,保温时间为30min时,两相的晶粒尺寸比较细小,此时磁性能最好,达到Br=1.06T,Hci=347kA/m,(BH)m=142kJ/m3。Nanocomposite Nd2Fe14B/a-Fe magnetic material was prepared by the mechanical milling and a subsequent crystallization vacuum annealing treatment with the as-cast alloy of Nd2Fe14B atomic ratio and a-Fe. The effects of milling and crystallization conditions on the microstructure and magnetic properties were investigated by X-ray diffractometer （XRD）, differential scanning calorimetry （DSC）, and transmission electron microscropy （TEM）, respectively. It was found that the grain sizes of both the Nd2Fe14B and the a-Fe phases decreased drastically with increasing the milling time. After milling for 5 h, the as-milled material was comprised of a-Fe nanocomposite phases of about 10 nm in size and some amorphous phases, which could be turned into the Nd2Fe14B/a-Fe nanocomposite phases by the subsequent crystallization annealing treatment. High magnetic properties could be achieved by the optimization of crystallization treatment process. In the present study, the best magnetic properties determined by PPMS were Br=1.06 T, Hci=347 kA/m, and （BH）m=142 kJ/m^3, respectively, when the material was milled for 5 h, followed by an annealing treatment at 650 ℃ for 30 minutes.

关 键 词：机械球磨 晶化处理 Nd2Fe14B/a—Fe纳米复相 微观组织 磁性能 

分 类 号：TM273[一般工业技术—材料科学与工程]