钕铁硼永磁材料的性能及研究进展

钕铁硼磁体被称为第3代稀土永磁材料,烧结钕铁硼磁体是目前综合磁性能最高的永磁材料。概述了钕铁硼永磁材料的研究进展和应用领域,介绍了钕铁硼磁体的性能及先进制备工艺,指出了目前国内钕铁硼磁体存在的主要问题及今后的研究方向。     

浅谈粘结永磁材料

介绍了粘结永磁体的趋势和现状,着重讨论了其应用领域以及未来前景,阐明了粘结永磁材料以其特有的性能,将成为新一代永磁材料。     

磁性复合材料的研究现状

磁性复合材料主要分为永磁复合材料和软磁复合材料两大类。稀土永磁材料是最早发展起来的永磁材料，一直占据主流地位。它是稀土元素和过渡族金属形成的一类高性能永磁材料，其性能特征是磁化强度高，剩余磁感应强度高，矫顽力性能较好，且是目前种类最多和应用最广的磁性材料。这类材料径历了SmC05、Sm2Co17、Nd2Fe14 B等3个发展阶段，目前Nd—Fe—B永磁材料以其高性能、轻型和微型的特征独占鳌头。目前有报道称可以得到磁能积达558．4kJ／m^3的烧结NdFeB永磁体，但其加工性能较差。     

挖掘钟表业加工潜力开发精密高档永磁元件

随着我国磁性材料工业的发展,永磁材料元件加工业得到了长足的发展,使永磁材料在各行各业的应用成为可能和现实。永磁元件特别是作为精密小型元件的加工,由于永磁材料的特殊性能——高硬度(铁氧体硬度达HRC70以上)、高脆性等决定了该加工行业的特殊性,不是一般机械加工行业能够胜任的。     

纳米晶复合NdFeB永磁材料研究进展

简要介绍了交换耦合作用及矫顽力的钉扎理论和成核理论,同时将目前实际制得的纳米晶复合NdFeB永磁体与理想模型进行对比分析,得出实际磁体性能与理论值相差很大的原因;从合金的成分优化和制备工艺优化两个方面,就近年来纳米晶复合NdFeB永磁材料的科技发展状况,作简要的评述;最后对纳米晶复合NdFeB永磁材料的行业发展现状进行了分析。     

稀土钴永磁在扬声器中的应用

为了使收音机袖珍化,需要小而薄的扬声器。为此已研制出新型永磁材料——稀土钴永磁。本文简介了稀土钴永磁的性能和用稀土钴永磁制成的动磁式扬声器、平板型扬声器、轻薄型电动扬声器的情况。     

卷首语

众所周知,过去十多年中永磁电机发展迅速,在国民经济中获得广泛应用。尤其是稀土永磁材料的应用,大大提高了永磁电机的性能,使其具有更加广阔的应用前景。对永磁电机相关领域的研究也成为大家关注的热点。本期从2007年德国纽伦堡PCIM欧洲会议中遴选了五篇与永磁电机     

外磁式铁氧体扬声器磁路设计方法

本文提出了外磁式永磁铁氧体扬声器磁路的设计方法,包括理论推导、设计要求、设计步骤及磁路测量等,并用实例说明了设计计算过程。文中还对各种永磁铁氧体材料的性能特点,国产材料性能指标和磁性材料性能的测量方法等提出了有用的数据和分析意见。这些内容可供扬声器磁路设计人员参考。     

钕铁硼稀土永磁材料及其在微特电机中的应用

本文介绍了钕铁硼稀土永磁材料的性能特点、制造工艺、应用钕铁硼稀土永磁的微特电机的特点和种类，以及存在的问题和改进措施。     

基于强磁场下永磁材料磁滞特性的数值模拟

在永磁材料推广应用的过程中,其性能使用程度的提升成为了当前关注的焦点。另外,永磁材料在特殊材质下产生的磁场效应,也是行业研究的重点内容。只有事前充分模拟永磁材料的磁特性,后期实际的磁体结构所产生的真实磁场与计算出磁场的误差才会尽可能的降低,这样才能设计出符合实际生产所需的永磁体。本文基于强磁场下永磁材料磁滞特性的数值模拟有关问题研究,希望能够最大程度上克服传统简化模拟方法在强磁场永磁体数值计算中出现的误差问题,提升精准度,有效指导实践工作。     

Modern permanent magnets for applications in electro-technology

The range of materials and properties now at the disposal of design engineers is described. Current uses of permanent magnets are reviewed, with particular attention to engineering and economic aspects. The rapid broadening of magnet uses is now occurring as traditional devices are miniaturized, and new applications and design concepts evolve. Currently evolving materials and production processes, prospects for still `better' magnets, and ultimate upper limits for permanent magnet properties are assessed     

Use of permanent magnets and magnetic fluids in experimental oncology

The use of permanent magnets and magnetic fields (magnetic fluids and magnetic suspensions) alone or in complex with the antitumour compounds for the treatment of malignancies of various localizations is considered. Methods and forms of the use of permanent magnets are discussed. It is concluded that permanent magnets (as magnetic suspensions and magnetic fluids) used alone, in complex with chemical substances or in combination with other affecting factors (the temperature rise) induce a considerable regression of the tumour. Besides, permanent magnets may promote an increase of the antitumour drug concentration in the tissue of the diseased organ.     

干压磁场成型永磁铁氧体特性及其制造

简要介绍了永磁铁氧体的结构和磁特性，并结合实际生产工艺就干压磁场成型制造永磁铁氧体的过程提出了一些看法。     

Method for temperature compensation of magnetic elements

With the establishment of a mechanical link between components of materials differing in their respective magneto-elastic properties and temperature indexes of linear distension, mechanical pressures take place, which are functually dependent on temperature. The effect of these pressures on the magnetic properties of magnetic conductors or permanent magnets formed in this manner compensates for the variations of magnetic permeability caused by temperature deviations.     

Design of a linear bulk superconductor magnet synchronous motor for electromagnetic aircraft launch systems

High-temperature superconducting (HTS) material in bulk form is used to design a linear synchronous motor for an electromagnetic aircraft launch system. The motor is designed without an iron core. Stator coils are placed in the air while the permanent magnets used in conventional design of linear permanent magnet synchronous motors are replaced by the HTS bulk magnets. The physical, operational, and equivalent circuit parameters of the linear motor with HTS bulk magnets are compared with those of a linear permanent magnet synchronous motor and linear induction motor designed for the same application. Results show that utilizing superconducting magnets is only superior at temperatures below 40 K.     

低温度系数永磁材料

正 在微波器件和精密仪器中,要求所用的永磁材料在很宽的温度范围内磁通基本保持不变,亦即要求所用的永磁材料具有很低的可逆温度系数()。铝镍钴、铁氧体、铂钴和普通的稀土钴永磁材料均不能满足上述要求。我们根据轻稀土钴和重稀土钴化合物的磁化强度随温度变化的相反性质,即轻稀土钴化合物的磁化强度随温度增加而降低,而重稀土钴化合物的磁化强度在一定温度范围内随温度增加而增加。通过用重稀土Gd、Er取代SmCo5中一部分Sm,并适当调节Sm与Gd、Er之间的比例,制备成了可逆温度系     

钐钴永磁材料在行波管中的应用

介绍了行波管中永磁材料的选择，Sm2Co17型永磁材料的稳定性，以及测试中极靴、极靴厚度和外径对磁场的影响等。与其它永磁材料相比，Sm2Co17型永磁材料稳定性好，是一种理想的行波管聚焦磁性材料；实验表明：磁环两端加上极靴后，轴向磁场将得到提高，而且极靴外径对磁场的影响比厚度大。     

Linear Permanent Magnet Oscillatory Machine: Comprehensive Modeling for Transients With Validation by Experiments

A linear and respective nonlinear state space model of a linear permanent magnet oscillatory machine is defined and then its parameters are computed from tests. The experiments were performed on two linear machine prototypes, one with interior permanent magnets and flux concentration and the other with surface permanent magnets. The finite element method model, validated on the existing prototype, shows further improvement possibilities of the interior permanent magnet machine. Dynamic tests and simulations with mechanical coupling of the two machines are used to validate the model in motion and on load. Good agreement between theory and tests in terms of various variables, including the linear position measured with a Laser-based transducer, has been observed.