检索结果-南通市图书馆

Journal of Rare Earths 2022年第6期40卷 924-929,I0003页

作者： Jinhao Zhu guangfei ding Lei Jin Zhehuan Jin Bo Zheng Shuai Guo Renjie Chen Aru Yan CAS Key Laboratory of Magnetic Materials and Devices and Zhejiang Province Key Laboratory of Magnetic Materials and Application TechnologyNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China

In this study,we propose an approach of grain boundary modification that can significantly increase the coercivity of the B-lean Nd-Fe-B sintered magnets by intergranular addition of *** coercivity is substantially enhanced from 1.51 to 2.04 T through optimizing the microstructure and adjusting the phase composition for the grain boundary phase in the annealed *** matrix grains are covered by a continuous thin grain boundary phase accompanying the formation of intermetallic Nd_(6)Fe_(13)Ga *** analysis of magnetic behaviors above Curie temperature confirms that the grain boundary phase of annealed Nd-Ga doped magnets appears to be non-ferromagnetic,facilitating the intergrain exchange *** observation in grain boundary area indicates that some surface of the matrix grain is dissolved in the formation process of the Nd_(6)Fe_(13)Ga *** gives rise to a decrease in the proportion of matrix grains and saturation magnetization of the *** detailed relationship between magnetic properties and microstructure is discussed based on these results.

关键词： Nd-Fe-B sintered Magnet Magnetic properties Grain boundary Microstructures Rare earths

Effect of yttrium substitution on magnetic properties and service performances of Nd-Fe-B sintered magnets

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2023年第1期41卷 116-121页

作者： Xiaodong Fan Shuai Guo guangfei ding Sining Fan Zhehuan Jin Renjie Chen Shukai Zhang Aru Yan CAS Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo 315201China Chinalco Shandong Yinuowei Strong Magnetic Material Co. LtdTaian 271600China

We successfully fabricated partial Y substituted NdY-Fe-B magnets with nominal compositions of(Nd_(1-x)Y_(x))_(13.80)Fe_(ba1)Al_(0.24)Cu_(0.1)B_(6.04)(at%,x=0,0.1,0.2,0.3,0.4) by powder metallurgy process and the magnetic properties as well as service performances of the magnets were also systematically *** phase constituents of the magnets have no obvious variation within the whole range of Y content,while the main phase grains form in-situ core-shell structure where Y gathers in the core and Nd mainly distributes in the *** with pure Nd-Fe-B magnets,the magnetic performances of Y substituted magnets slightly decrease on account of the poor intrinsic magnetic properties of Y_(2)Fe_(14)***,the μ_(O)M_(r),μ_(O)H_(cj) and(BH)_(max) of the 20 at% Y magnet still remain at a high level of 1.325 kG,1.173 kOe and 342.884 kj/m^(3),which approaches the performances of commercial N45-grade *** service performances of Y substituted magnets indicate that though the surface corrosion products and Vickers hardness of the NdY-Fe-B magnets increase to a certain extent compared to Nd-Fe-B,the magnets with Y substitution still display relatively good service ***,on the basis of sacrificing little partial magnetic and service performances,Y substituted Nd can still prepare NdY-Fe-B medium-grade *** this way,we achieve the balanced utilization of rare earth resources,which has significant meanings for the industry and scientific research.

关键词： Y substitution Magnetic properties Service performances Nd-Fe-B sintered Magnets Rare earths

A comparative study of NdY-Fe-B magnet and NdCe-Fe-B magnet

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第9期40卷 1480-1487,I0006页

Low cost and high abundance rare earth elements Y and Ce have attracted tremendous interests of the industrial and scientific societies for fabricating the highly cost-performance efficient rare earth permanent ***,the effect of separate replacement of Nd by Y or Ce on the performances of NdFeB-type magnet under the same atomic ratio and preparation conditions is still *** this work,we systematically investigated the magnetic properties,thermal stabilities and service performances of(Nd_(0.8)Y_(0.2))_(13.80)Fe_(bal)Al_(0.24)Cu_(0.1)B_(6.04)(atomic fraction,denoted as 20 Y)and(Nd_(0.8)Ce_(0.2))_(13.80)Fe_(bal)Al_(0.24)Cu_(0.1)B_(6.04)(atomic fraction,denoted as 20 Ce)*** results demonstrate that theμ_(0)M_(r),μ_(0)H_(c)and(BH)_(max)of 20 Y magnet are respectively 1.325 T,1.173 T and 343.467 kJ/m^(3),which are comprehensively higher than those of 20 Ce magnet(μ_(0)M_(r)=1.310 T,μ_(0)H_(c)=0.948 T,(BH)_(max)=321.105 kJ/m^(3)).Moreover,the 20 Y magnet has higher thermal stability compared with 20 Ce magnet which is favorable for the magnetic performances at elevated *** investigation of micro structure and elemental distribution indicates that the excellent magnetic performance s of NdY-Fe-B magnet can be attributed not only to the preferable intrinsic properties4πM_(s),H_(s)and T_(c)of Y_(2)Fe_(14)B,but also to the in-situ co re-shell structure of the 2:14:1 matrix phase grain with Yrich core and Nd-rich shell,along with the thicker grain boundary layer between the adjacent matrix phase grains in NdY-Fe-B ***,the 20 Y magnet exhibits better mechanical property and higher corrosion resistance than 20 Ce magnet,which are helpful for prolonging the service life of the magnet in practical application.

关键词： NdY-Fe-B NdCe-Fe-B Magnetic properties Thermal stabilities Service performances Rare earths

Influence of Pr-Al-Co alloy diffusion source on magnetic properties and microstructure of sintered Nd-Fe-B magnets processed by grain boundary diffusion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第12期40卷 1885-1893,I0003页

作者： Lei Jin Jinhao Zhu guangfei ding Zhehuan Jin Bo Zheng Xuejing Cao Shuai Guo Renjie Chen Aru Yan Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Material Technologyand EngineeringChinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China

In this study,the influence of the content of Al and Co in the diffusion source on the magnetic performance and microstructure of the diffused magnet was studied by grain boundary diffusion treatment with Pr_(70)Al_(30-x)Co_(x)(x=0 at%,10 at%,15 at%,20 at%,30 at%)*** the Co content in the diffusion source increases from 0 at%to 10 at%,the coercivity enhancement in the Pr_(70)Al_(20)Co_(10)diffused magnet is the highest,increased from 1.62 to 2.24 T,higher than 2.01 T of the Pr_(70)Al_(30)diffused *** further increase of Co content in the diffused source,the coercivity of the diffused magnet decreases gradually,the coercivity of Pr_(70)Al_(15)Co_(15),Pr_(70)Al_(20)Co_(10)and Pr_(70)Co_(30)diffused magnet is 2.15,1.99 and1.81 T,*** analysis shows that plenty of continuous grain boundary phases(CGBPs)can be formed in the Pr_(70)Al_(20)Co_(10)diffused magnet under the synergistic effect of Al and Co,which leads to the enhancement of magnetic isolation between more adjacent ***,the amount of CGBP in the diffused magnets gradually decreases with the further increase of Co content in the diffusion source.

关键词： Nd-Fe-B Coercivity Pr-AI-Co alloys Grain boundary diffusion Rare earths

Effects of Pr-Cu-Ti intergranular addition on microstructure and magnetic properties of heavy-rare-earth-free Nd-Fe-B sintered magnets

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第5期40卷 778-783,I0004页

作者： Jinhao Zhu guangfei ding Bo Zheng Haichen Wu Lei Jin Zhehuan Jin Shuai Guo Renjie Chen Aru Yan CAS Key Laboratory of Magnetic Materials and Devices and Zhejiang Province Key Laboratory of Magnetic Materials and Application TechnologyNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China Analytical Center Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China

By intergranular addition of Pr-Cu-Ti alloy powders in the Nd-Fe-B sintered magnets with the normal B component,we propose an approach to the optimization of grain boundary and local Nd-Fe-B composition *** coercivity is enhanced from 1.42 to 1.86 T,while further addition leads to a reduction in remanence and *** analyses of phase composition reveal that Ti mainly exists in the form of metallic Ti alloy,and part of Ti combines with B to form the TiB2 phase after the liquid phase sintering *** process results in a consumption of B in the local Nd-Fe-B composition system and a change of the grain boundary component,which contributes to the formation process of the RE_(6)(Fe,M)_(14) phase after the annealing ***,with the modification of grain boundary and composition system,the intergranular addition of Pr-Cu-Ti induces the generation of continuous thin grain boundary *** promotes the intergrain exchange decoupling,increasing the coercivity in the annealed *** the excess addition results in the segregation of TiB_(2),as well as the precipitation of TiB_(2) into the Nd-Fe-B phase,which leads to structural ***,the further effort for the addition alloy with Ti to reduce the deterioration of the microstructure will lead to further improvement in magnetic properties.

关键词： Nd-Fe-B sintered magnet Magnetic properties Grain boundary Microstructures Rare earths

Microstructural design in LaCe misch-metal substituted 2:14:1-type sintered magnets by dual-alloy method

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2021年第3期39卷 305-311,I0003页

作者： Kan Chen Shuai Guo Hongliang Zhao Xiaodong Fan Fengchun Fan guangfei ding Renjie Chen Xiwen Zheng Aru Yan Key Lab of Magnetic Materials and Devices Ningbo Institute of Macerials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Ningbo Tongchuang Strong Magnet Material Co. Ltd.Ningbo 315201China

LaCe-based sintered magnets with different microstructural features and distinct rare earth elemental distribution were designed by dual-alloy *** sample prepared by fine LaCe-containing powder and coarse LaCe-free powder possesses higher remanence(~13.41 kGs),whereas another sample prepared by fine LaCe-free powder and coarse LaCe-containing powder possesses higher coercivity(~5.67 kOe).Additionally,these samples are with the same nominal compositions and their elemental distribution features are obviously different in matrix grains *** remanence difference is mainly affected by the saturation magnetization difference caused by the distribution variation of the rare earth elements at the matrix *** coercivity difference is affected by the component of the grain boundary phase between the adjacent grains and the distribution variation of the rare earth elements at the matrix *** findings may provide a new prospect for the utilization of LaCe mischmetal in 2:14:1-type permanent magnets.

关键词： Misch-metal Microstructural design Sintered magnet Rare earths

Improved corrosion resistance and thermal stability of sintered Nd-Fe-B magnets with holmium substitution

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2018年第8期36卷 826-831页

作者： Jinghui Di Shuai Guo Ling Chen Pengpeng Yi guangfei ding Kan Chen Ming Li Don Lee Aru Yan Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Material Technology and Engineering Chinese Academy of SciencesNingbo 315201China Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology Ningbo Institute of Material Technology and Engineering Chinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China Ningbo Songke Magnetic Material Co. Ltd.Ningbo 315517China University of Dayton.OH 45469 USA

The effects of Ho substitution for Nd on the microstructure, corrosion resistance and thermal stability of the Nd-Fe-B magnets were investigated. The（Nd,Ho）-O phase was formed with increasing Ho substitution. The results of potentiodynamic polarization and highly accelerated stress test show improved corrosion resistance with increasing Ho substitution. The optimum mass loss 0.29 mg/cm^2 is ***, the average temperature coefficients for remanence and coercivity in the range of 25-150℃are both closer to zero, indicating improved thermal stability. The mechanisms for the improved corrosion resistance and thermal stability are discussed in relation to the microstructure featuring the（Nd,Ho）-O phase.

关键词： Corrosion resistance Ho substitution Nd-Fe-B Thermal stability Rare earths

在线全文

学校读者我要写书评

暂无评论

高丰度钇在永磁材料中的应用研究

中国稀土学报 2021年第3期39卷 425-435页

作者：闫阿儒丁广飞郭帅郑波陈仁杰中国科学院宁波材料技术与工程研究所浙江宁波315201

促进高丰度元素在稀土永磁材料中的应用是推动中国稀土资源平衡利用的重要举措,目前针对高丰度La, Ce磁体的研究已经取得一定的进展,而高丰度Y元素在永磁材料中的研究相对不足。获得稳定的物相结构和理想的微观组织结构是发展低成本高... 详细信息

促进高丰度元素在稀土永磁材料中的应用是推动中国稀土资源平衡利用的重要举措,目前针对高丰度La, Ce磁体的研究已经取得一定的进展,而高丰度Y元素在永磁材料中的研究相对不足。获得稳定的物相结构和理想的微观组织结构是发展低成本高性能稀土永磁材料的关键。本课题组的研究表明:通过小原子半径的Y元素取代,能够稳定形成主相的四方结构,同时避免晶界杂相的生产;Y元素较强的主相形成能力能够促进Y取代磁体中天然的核壳组织结构的形成,进一步通过Y/Ce的共同取代,能够实现对高丰度元素在磁体内分布行为的调控;通过设计富稀土含镓的合金成分,在15%Y(原子分数)取代Nd的条件下获得1.72 T的室温矫顽力,同时磁体具有较好的矫顽力热稳定性,与商业的含Dy磁体相当。

关键词：高丰度Y 永磁材料微观结构磁性能

在线全文

学校读者我要写书评

暂无评论

高丰度稀土永磁材料的研究进展与展望

中国稀土学报 2023年第1期41卷 79-90页

作者：闫阿儒贾智曹帅丁广飞郭帅陈仁杰中国科学院宁波材料技术与工程研究所浙江宁波315201 中国科学院大学北京100871

稀土永磁材料的大量使用导致低丰度、高成本稀土元素Pr,Nd,Dy,Tb等过度消耗,而高丰度稀土元素La,Ce,Y未得到充分利用,导致稀土元素利用的严重失衡,不利于中国稀土资源利用的健康持续发展。出于国家战略安全和原材料成本角度考虑,低成本... 详细信息

稀土永磁材料的大量使用导致低丰度、高成本稀土元素Pr,Nd,Dy,Tb等过度消耗,而高丰度稀土元素La,Ce,Y未得到充分利用,导致稀土元素利用的严重失衡,不利于中国稀土资源利用的健康持续发展。出于国家战略安全和原材料成本角度考虑,低成本、高性能的高丰度稀土永磁材料的研究与开发势在必行。本文对高丰度稀土永磁材料的研究现状进行归纳总结,分别介绍了富Ce磁体、富La,Ce磁体及富Y磁体的微观结构特征及其性能调控技术,并对高丰度稀土永磁材料的开发进行了讨论和展望。

关键词：稀土永磁材料高丰度稀土微观结构磁性能

Effect of In doping on the evolution of microstructure,magnetic properties and corrosion resistance of NdFeB magnets

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 623-629页

作者：李豫豪范晓东贾智范璐丁广飞刘新才郭帅郑波曹帅陈仁杰闫阿儒 School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China

The grain boundary phase affects the magnetic properties and corrosion resistance of sintered NdFeB *** this work,a small amount of In was added to NdFeB magnets by induction melting to systematically investigate its effect on the evolution of the microstructure,magnetic properties and corrosion resistance of NdFeB *** analysis illustrated that minor In addition generated more grain boundary phases and an abundant amorphous phase at the triple-junction grain *** the addition of In failed to enhance the magnetic isolation effect between adjacent matrix grains,its incorporation fortuitously elevated the electrochemical potential of the In-containing ***,during corrosion,an In-rich precipitate phase formed,hindering the ingress of the corrosive medium into the ***,this significantly bolstered the corrosion resistance of the sintered NdFeB *** phase formation,magnetic properties and corrosion resistance of In-doped NdFeB magnets are detailed in this work,which provides new prospects for the preparation of high-performance sintered NdFeB magnets.

关键词： In-doping NdFeB magnets magnetic properties corrosion resistance