MnZn软磁铁氧体材料的制备

【作者】 李拓；

【导师】 陈一胜； 赵晓举；

【作者基本信息】 江西理工大学 ， 材料工程， 2010， 硕士

【摘要】 由于高磁导率铁氧体材料的磁导率很高,较少的线圈匝数就可以获得较高的电感量,磁芯可以很小,因此,高磁导率铁氧体材料能够满足器件和系统小型化和轻量化的要求。此外,高磁导率软磁铁氧体磁芯还能有效地吸收电磁干扰信号,达到抗电磁干扰的目的。随着电子产品普遍应用于人们的日常生活,电磁干扰问题日趋严重今,研究高磁导率铁氧体材料是解决这个问题的主要途径之一。随着21世纪信息技术和电子产品数字化的发展,国内对高磁导率铁氧体材料的需求量猛增,它的产量已经占据软磁铁氧体产量的30%以上。由于其技术含量高,附加值高,市场竞争激烈,所以,高磁导率材料的研究一直是国内外的重点。本论文主要对R12K高磁导率MnZn铁氧体材料的氧化物陶瓷制备工艺进行了研究。在论文中,研究了Fe2O3、ZnO含量对样品磁性能参数(如起始磁导率μi、饱和磁感应强度Bs、剩余磁感应强度Br和矫顽力Hc)的影响,确定了R12K软磁材料的最优配方;并在此基础上研究了球磨转速、预烧温度对材料微观结构和磁性能的影响;此外还采用正交实验方法分析了添加剂CaCO3、V2O5、Bi2O3和MoO3对材料性能的综合作用。研究结果表明:1、随着配方中Fe2O3含量的增加,起始磁导率先上升后降低,饱和磁感应强度呈下降趋势,矫顽力总体上升。2、随着配方中ZnO摩尔含量的增加,起始磁导率和剩余磁感应强度均先上升后降低,饱和磁感应强度和矫顽力呈下降趋势。3、通过正交实验确定最佳配方为Fe2O3: ZnO: MnO =52:22:26 (mol%)4、球磨转速过高或太低都会使粉料颗粒难以被有效碾磨,混合均匀,从而影响高磁导率MnZn铁氧体材料的磁性能,适宜二次球磨转速为r=210r/min。5、添加适量V2O5(0.06wt%)可以有效改善材料的综合性能:由正交实验法确定的添加剂最佳比为CaCO3 : Bi2O3 : MoO3 : V2O5(wt%)=0.02 : 0.05 : 0.06 : 0.02。6、随着预烧温度的升高,起始磁导率先上升后降低,饱和磁感应强度下降,在840℃左右预烧,材料的起始磁导率和饱和磁感应强度较高。更多还原

【Abstract】 High permeability materials can meet the requirements of miniaturization and lightweight of devices and systems because based on them less coils can get higher inductance due to their high permeability and smaller core. At the same time, the ferrite cores with high permeability can effectively absorb the electromagnetic interference signals, which can achieve the goal of anti-electromagnetic interference. With the electron products generally applied to the daily life, the problems of electromagnetic interference are becoming more and more serious, so investigation of high permeability materials is one of the good means to resolve this problem. Due to the development of information technology and electron product, the requirement of the high permeability materials increased sharply and their output reached 30 percent of the overall yield of ferrite. Thus study on the high permeability materials is the focus of the research in the world because of its high technical skills and addedvalue.In this paper, the conventional ceramic process of the R12K MnZn ferrite were studied. In the experiment, the effect of Fe2O3 and ZnO on the magnetic properties of ferrites, such as initial permeability (μi), saturation magnetic induction (Bs) was considered and the best formula of R12K MnZn ferrite was confirmed. Based on this formula, the influence of calcining temperature and rate of ball milling on initial permeability (μi), saturation magnetic induction (Bs), residual magnetic induction (Br) and coercive force (Hc) was discussed in detail. Furthermore, We analyzed the associated influence of dopants (CaCO3 ,V2O5 ,Bi2O3 and MoO3) on the magnetic properties of ferrites by adopting orthogonal design scheme. The main results were shown as follows:1、With the Fe2O3 content of the prescription increasing,μi showed the changing tendency of increasing at first and then decreasing, but Bs was always decreased and Hc was always increased.2、With the ZnO content of the prescription increasing,μi and Br were both increased at first and then decreased, but Bs and Hc were both decreased.3、The optimal mol ratio of Fe2O3, ZnO and MnO was 52 : 22 : 26.4、The rotational speed of a ball mill being too fast or too slow both lead to difficult grinding and mixing of powder particles, which could influence the magnetic properties of MnZn ferrite. The experiment results showed that the suitable secondary rotational speed was 210 r/min.5、Appropriate additive amount of V2O5 (0.06 wt%) can improve the comprehensive performance of materials. By the orthogonal design scheme, the optimal proportions of CaCO3 : Bi2O3 : MoO3 : V2O5 (wt%) is 0.02 : 0.05 : 0.06 : 0.02.6、The increasing of calcining temperature had an important effect onμi and Bs. Calcined under 840℃,μi and Bs of materials were both high.更多还原