共查询到19条相似文献,搜索用时 140 毫秒
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介绍了铂钴永磁合金的相结构及磁性能,并分析了磁性能与相结构的关系;概述了铂钴合金的制备方法和其典型的永磁性能,对比了国内外铂钴永磁材料的研究进展情况。最新的研究结果表明,铂钴永磁材料为软磁相和硬磁相耦合的微结构,因此铂钴永磁合金为研究纳米晶交换耦合机理提供了一个理想的模型。 相似文献
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Co/Nb复合添加对Nd2Fe14B/α-Fe纳米晶双相复合永磁体的影响 总被引:1,自引:1,他引:0
通过复合添加,采用熔体快淬法制备Nd8 Fe82 Co3 Nb1 B6纳米晶双相复合永磁体,研究了Co,Nb对合金微观组织及磁性能的影响.结果表明,合金元素Co/Nb的复合添加,可降低剩磁和矫顽力的温度系数,增强软、硬磁相的高温稳定性;其次,提高合金的非晶形成能力,在合金的晶化退火处理中促进晶粒细化,改善显微组织,增加两相晶粒间的铁磁交换耦合作用,有利于合金综合磁性能的提高,其最佳磁性能为Br=1.14 T,Hcj=320 kA·m-1,(BH)max=109.3 kJ·m-3. 相似文献
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探讨了显微组织对纳米复合永磁材料的矫顽力、剩磁和最大磁能积的影响.得出了要同时得到良好的磁性能,须综合考虑晶粒尺寸和软磁性含量.设计纳米复合磁体的原则应该是:软磁相和硬磁相的晶粒尺寸分别控制在10 nm和20 nm左右,软磁性含量控制在30%~40%,而且两者之间充分交换耦合. 相似文献
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纳米复相稀土永磁材料研究进展 总被引:1,自引:0,他引:1
综述了纳米复相稀土永磁材料的研究现状;详细介绍了纳米复相永磁体的制备方法及磁性能,在粘结磁体、快淬磁体和磁控溅射磁体的基础上,又详细介绍了制备大块致密磁体的方法:热压法和热挤压法.分析了各种制备方法的优缺点;论述了添加合金元素和热处理工艺对磁性能的影响.并对纳米复相稀土永磁材料的研究前景作了展望. 相似文献
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纳米晶复合永磁合金是近年来稀土永磁材料领域研究的热点之一。它具有与其它各向同性稀土永磁体不同的磁硬化机制和综合高磁性能。本文介绍了这类永磁合金的发展历程,并对其理论和实验方面的研究现状作了简要综述。 相似文献
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磁温度补偿合金对永磁体补偿效果的表征 总被引:2,自引:0,他引:2
采用外补偿法改善Nd-Fe-B永磁材料的磁性能温度稳定性。讨论了磁温度补偿合金与永磁体组合后的磁性能和温度稳定性的表征。研究表明:用组合磁体的最大磁能积可以表征其磁性能,用开路法测试的可逆磁通温度系数可表征组合磁体的磁性能温度稳定性。用本实验室开发的磁温度补偿合金得到的组合磁体的可逆磁通温度系数小于0.001%/℃(20~100℃),室温下的最大磁能级达到195 kJ.m-3。外补偿法不仅能够有效地改善Nd-Fe-B永磁材料的磁性能温度稳定性,而且能够保持较高的磁性能。 相似文献
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SmCo_5稀土永磁材料在纳米级别时可以获得高的矫顽力和强烈的磁耦合特性,在超高密度磁记录材料、高性能永磁材料和纳米复合材料等领域具有重要应用。然而,低的剩磁限制了SmCo_5永磁材料的发展。软硬磁双相纳米复合材料的出现弥补了其低剩磁的不足,为高性能高使用温度永磁材料的发展提供了重要基础,在航空航天、电动汽车以及风力发电等领域具有潜在的应用。采用物理法或化学法可以制备出SmCo_5纳米粒子及其纳米复合粒子,这些方法具有各自的优点,也存在明显的不足。介绍了SmCo_5纳米粒子的矫顽力机制和相应的制备方法(包括物理法和化学法),并对各方法的优缺点进行了总结和对比。同时,综述了SmCo基纳米复合粒子的交换耦合作用机制以及它们的研究现状;通过对三类模型进行分析,阐明了纳米复合材料所面临的问题,指出了未来纳米复合材料的研究方向。 相似文献
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Rare earth permanent magnetic materials are typical electrical conductor, and their magnetic properties will decrease because of the eddy current effect, so it is difficult to keep them stable for a long enough time under a high frequency AC field. In the present study, as far as rare earth permanent magnets are concerned, for the first time, rare earth permanent magnets with strong electrical insulation and high magnetic performance have been obtained through experiments, and their properties are as follows: (1) Sm2TM17: Br=062 T, jHc=8037 kA/m, (BH)m=5897 kJ/m3, ρ=7 Ω·m; (2) NdFeB: Br=0485 T, jHc=76633 kA/m, (BH)m=3796 kJ/m3, ρ=9 Ω·m. The magnetic properties of Sm2TM17 and NdFeB are obviously higher than those of ferrite permanent magnet, and the electric insulating characteristics of Sm2TM17 and NdFeB applied have in fact been approximately the same as those of ferrite. Therefore, Sm2TM17 and NdFeB will possess the ability to take the place of ferrite under a certain high frequency AC electric field. 相似文献
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Rare Earths and Magnetic Refrigeration 总被引:4,自引:2,他引:2
Modern coolingis almost entirely based on a com-pression/expansion refrigeration cycle .It is a high-en-ergy demand industry with annual energy consumptionmeasured in billions kWh.Over the years ,all parts ofa conventional refrigerator ,i .e ., compressors , heatexchangers , refrigerants , and packaging have beenconsiderably i mproved by an extensive research anddevelopment effort ,and partly by government edicts .This was made possible by a continuous dollar influxfromboth federal and industr… 相似文献
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Review on Rare Earth/Polymer Composite 总被引:4,自引:0,他引:4
The epecial properties of rare earth/polymer composite were described.More emphasis was put on the radiation shielding and magnetic properties,In the application to X-ray shielding,rare earth/polymer composite can make up the feeble absorbing area.If the rare earth content is high enough,it can demonstrate strong ability for thermal neutron absorption,The composite has strong paramagnetism.The feasibility of preparing magnetic rare earth/polymer compostite was discussed,In addition,three preparation methods were introducde:simlle polymerization,mixing and reaction processing,The effect of the rare earth/polymer composties pre-sturcture and the coordinate number of rare eatrh ions on the light property was analyzed,Rare earth/polmer compostie may have the structure and property simlar to those of the ionomer,The feasibility of the in-situ preparation of the rare earth/polymer nano structure is indicated ,Besides,the relationship between struchture and properties of the rare earth/polymer composite was discussed,The problems associated with such composite materials were also presented. 相似文献
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随着稀土永磁材料应用领域的扩大及需求量的猛增,导致关键稀土元素(Pr、Nd、Dy、Tb)的过度使用,而高丰度稀土元素(La、Ce、Y)却不断积压.高丰度稀土永磁材料不仅可以降低成本,还可实现稀土资源综合平衡利用,出于国家战略安全和原材料成本角度考虑,高性价比的高丰度稀土永磁材料的研究与开发势在必行.近年来,大量学者对高丰度稀土永磁材料的高值化利用展开了广泛研究.然而,在不同成分合金中,其主相热稳定性、第二相种类、相析出行为、价态、微量元素的偏聚冶金行为等方面均与目前广泛使用的Nd基商业磁体存在较大差异.综述了高丰度稀土永磁材料的相结构、磁性能、微观结构和耐蚀性能等研究现状,并为其进一步开发与利用提出了建议. 相似文献
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粘结稀土永磁体的开发 总被引:2,自引:0,他引:2
本文简要叙述钢铁研究总院近年来对稀土永磁体的研制和开发工作。除了已经可以稳定大量生产和供应35H牌号的烧结NdFeB磁体外,在真空快淬工艺、HDDR工艺以及粘结磁体方面也进行了大量的研制工作。现在可以稳定生产供应高磁性能的磁粉和粘结磁体。此外,还简要报道了新一代稀土磁体SmFeN合金的研制状况。 相似文献
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《钢铁研究学报(英文版)》2006
In the paper, we summarize the USA research activities in the past two years on high performance rare earth (R)-based (nano) composite, nanostructured and hybrid permanent magnets. The work discussed is organized in three major sections (i) isotropic magnets based on the R2Fe14B hard phase, (ii) anisotropic magnets based on the R2Fe14B hard phase and (iii) magnets with a R-Co hard phase (1:5 and/or 2:17), including ultrahigh temperature Sm-Co magnets, Sm-Co permanent magnets with almost zero reversible temperature coefficient of residual induction for critical applications and ultrahigh temperature Sm-Co magnets with small reversible temperature coefficient of residual induction. 相似文献
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《钢铁研究学报(英文版)》2006
Innovative and cost-effective technology for synthesizing bulk anisotropic nanograin composite rare earth magnets has been developed. Using a powder blending technique, (BH)max of nanograin composite magnets can reach 40 to 50 MGOe, while applying powder coating techniques, (BH)max = 45–55 MGOe were achieved. Thus, principal technical difficulties in synthesizing bulk anisotropic nanograin composite magnets are successfully overcome. In addition, it was observed that the magnetically soft phase in a composite magnet could be up to tens of micrometers, or more than 1000 times larger than the upper size limit predicted by the current models of interface exchange coupling, which indicates that further reducing the size of the soft phase and improving its distribution will significantly improve the magnetic performance of nanograin composite magnets. 相似文献