通过改变二次球磨时间(1~6 h)调控原料粉体粒径,采用固相烧结法制备NiCuZn软磁铁氧体,研究了原料粉体粒径对软磁铁氧体微观结构和磁性能的影响。结果表明:粉体粒径随着二次球磨时间的延长而减小,尺寸分布逐渐集中;制备的软磁铁氧体晶粒尺寸的均匀性先变好后变差,晶界先变清晰后变模糊;随着粉体粒径的减小,NiCuZn软磁铁氧体的起始磁导率、饱和磁感应强度、相对密度及电阻率均先增大后减小,功率损耗先减小后增大;当二次球磨时间为3 h时,粉体粒径主要集中在2.5~3.5 μm,平均粒径为3.237 μm,烧结制备的软磁铁氧体的晶界较为清晰,晶粒尺寸均匀,起始磁导率、饱和磁感应强度最大,分别为1 385 H·m^-1和360 mT,功率损耗最小,为284 kW·m^-3。

NiCuZn soft magnetic ferrite was prepared by solid state sintering with raw powder of different particle size prepared by changing the secondary ball milling time (1-6 h). The effect of the particle size on the microstructure and magnetic properties of the soft magnetic ferrite was studied. The results show that the powder particle size decreased with the extension of secondary ball milling time, and the size distribution gradually concentrated. The uniformity of grain size of soft magnetic ferrite prepared became better and then worse, and the grain boundary became clear and then blurred. With the decrease of the powder particle size, the initial permeability, saturation magnetic induction intensity, relative density and resistivity of the soft magnetic ferrite increased first and then decreased, and the power loss decreased first and then increased. When the secondary ball milling time was 3 h, the powder partide size was mainly between 2.5-3.5 μm, with average particle size of 3.237 μm. At this time, the grain boundary of the prepared soft magnetic ferrite was relatively clear, and the grain size was relatively uniform. The initial permeability and saturation magnetic induction intensity reached the maximum value of 1385 H·m^-1 and 360 mT, respectively, and the power loss reached the minimum value of 284 kW · m^-3.