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Journal of Materials Science & Technology 2021年第26期85卷 56-61页

作者： Jun Cao Tianli Zhang Jinghua Liu Hao Xu Mingyao Hu Wei Xia Ao Wang Hui Wang Chengbao Jiang School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Increasing iron content has been witnessed an essential method to improve the remanence of 2:17-type Sm-Co-Fe-Cu-Zr magnets,however,the inferior squareness factor accompanied with the increased iron content turns into a neck sticking *** this work,the grain boundary optimization induced substantial squareness enhancement from 63.4%to 91.4%,and consequently an excellent maximum energy product of 32.63 MGOe have been achieved in iron-rich Sm-Co-Fe-Cu-Zr magnets via tuning solution *** is clearly revealed that the grain boundary(GB)phases as well as the micro-twins’density in grain interiors can be controlled and interprets the enhancement mechanism of squareness.

关键词： Iron-rich Sm-Co-Fe-Cu-Zr magnet Grain boundary squareness

Effect of Bath pH on the squareness of Electroless CoNiWP Magnetic Films

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Journal of Materials Science & Technology 2008年第5期24卷 712-714页

作者： Haibin CHENG Shuai XU Wenyu ZHAO Suling ZHAO Pengcheng ZHAI Zhigang SUNand Qingjie ZHANGt Pengcheng ZHAI Zhigang SUN Qingjie ZHANG State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Electroless CoNiWP magnetic films were prepared by varying the bath pH and then characterized by energy dispersive X-ray analysis, X-ray diffraction and magnetic force microscopy, it has been found that the microstructure and the magnetic properties of films were influenced greatly by the bath pH. At the bath pH 8.06, the grain size and coercivity of the films reach maximuml while the squareness （Mr/Ms） of MH curves reaches minimum. The Henkel plots indicates that the exchange-coupling interaction is very weak at this pH, which may be caused by phase-separation and large grain size, and then results in the lowest squareness. At pH above 8.5, obvious exchange-coupling interaction is observed because of the inexistence of phase-separation and the refinement of grain size.

关键词： CoNiWP magnetic film Bath pH squareness Exchange-coupling interaction

Correlation of microstructure and magnetic properties in Sm(Co_(bal)Fe_(0.1)Cu_(0.1)Zr_(0.033))_(6.93) magnets solution-treated at different temperatures

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Rare Metals 2019年第1期38卷 20-28页

作者： Cheng Xu Hui Wang Tian-Li Zhang Alexander Popov Raghavan Gopalan Cheng-Bao Jiang School of Materials Science and Engineering Beihang University M.N. Miheev Institute of Metal Physics Ural Branch of Russian Academy of Sciences International Advanced Research Centre for Powder Metallurgy and New Materials(ARCI) IITM Research Park

The correlation of microstructure and magnetic properties in Sm(Co_(bal)Fe_(0.1)Cu_(0.1)Zr_(0.033))_(6.93) magnets solution-treated at different temperatures was systematically investigated. It is found that the magnets solution-treated at 1219℃ possess a single 1:7 H phase, exhibiting the homogeneous cellular structure during further aging treatment, leading to the optimum magnetic properties. However, for the magnets solution-treated at 1211 and 1223℃,2:17 H or 1:5 H secondary phase will also form besides 1:7 H main phase, which cannot transform into cellular structure,thus deteriorating the magnetic properties greatly. The irreversible magnetization investigations with recoil loops also propose a non-uniform pinning in the magnets induced by the secondary precipitates. At proper solution temperature, Zr is supposed to occupy the Fe-Fe dumbbell sites in the form of Zr-vacancy pairs, leading to the minimum c/a ratio and thus stabilizing the 1:7 H phase. Finally,Sm(Co_(bal)Fe_(0.1)Cu_(0.1)Zr_(0.033))_(6.93) magnets with the maximum energy product and intrinsic coercivity at 550℃ up to 60.73 kJ·m^(-3) and 553.88 kA·m^(-1) were prepared by powder metallurgy method.

关键词： Sm2Co17 Solution treatment Phase constitution Demagnetization curve squareness

In-situ observation of magnetization reversal process of Sm(Co,Cu,Fe,Zr)_z magnets with different Fe contents

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Rare Metals 2020年第3期39卷 250-255页

作者： Shuo Wu Dong-Tao Zhang Ming Yue Yun-Qiao Wang Zhi-Feng Shang Dan Wu Jing-Ming Liang College of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing100124China

Sm(Co,Cu,Fe,Zr)z magnets have drawn much attention for high-temperature applications due to their high Curie temperature,strong corrosion resistance and thermal *** effect of increasing Fe content on the distribution of elements and squareness(Sr)of demagnetization curves were investigated for two kinds of magnets with different nominal compositions of Sm(CobalFe0.15-Cu0.07Zr0.03)7.8 and Sm(CobalFe0.28Cu0.07Zr0.03)6.6 in this *** magnetic properties of the magnets with higher Fe content fluctuate greatly after different solution treatments,indicating that they are more sensitive to the process *** increase in Fe content can obviously enhance the cellular phase ***,inhomogeneous Cu distribution is observed in the Sm(CobalFe0.28-Cu0.07Zr0.03)6.6 magnet,resulting in the different cellular structures and corresponding magnetic domain patterns in different regions in the inner ***,the lower Cu content regions are responsible for the wider magnetic domain,which have weaker resistance to applied magnetic *** a result,Sr of demagnetization curve decreases with the increase in Fe content due to the inhomogeneous Cu distribution,which was confirmed by in-situ observation of electron probe micro-analyzer(EPMA)and magneto-optical Kerr optical microscope(MOKE).

关键词： Sm(Co,Cu,Fe,Zr)_z magnets Cu distribution Microstructure Magnetic properties Magnetic domain squareness

Effect of yttrium substitution on magnetic properties and microstructure of Nd-Y-Fe-B nanocomposite magnets

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Journal of Rare Earths 2010年第2期28卷 277-281页

作者：陈治安罗骥隋延力郭志猛 Institute of Powder Metallurgy University of Science and Technology Beijing State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

The phase evolution,microstructure and magnetic properties of Nd9-xYxFe72Ti2Zr2B15(x=0,0.5,1,2) nanocomposite ribbons were *** was found that substitution of Y enhanced glass forming ability of the over-quenched ribbons and stabilized the amorphous phase during post annealing *** content of Y substitution effectively refined the microstructure and enhanced the remanence of the annealed *** residual amorphous intergranular phase in the annealed sample improved the square...

关键词： nanocomposite yttrium substitution glass forming ability residual amorphous phase squareness rare earths

Investigation of Abnormal Grain Growth in Sintered Nd-Fe-B Permanent Magnet

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Journal of Rare Earths 2004年第z1期22卷 112-114页

作者： Liu Guozheng Liu Shufeng Wu Bin Lu Weidong Zhao Mingjing Lu Fuqiang Zhao Ruijin Baotou Research Institute of Rare Earth Baotou 014010 China Inner Mongolia Xi Yuan Engineering and Technology Research Center of Rare Earth Fuctional Material Baotou 014010 China

The abnormal growth of grains of sintering Nd13.6 Dy0.4 Fe79.5 B6.5 magnets were investigated in low oxygen manufacturing *** abnormal growth of grains occurs easily when the sintering temperature is higher than 1080℃ during the manufacture *** the magnets, the oxygen content is less than 700 × 10-6 and the average particle size of powder is smaller than 4 μ*** squareness of demagnetization curve of magnet is *** high performance magnets, the abnormal growth grain should be avoided by selecting a suitable sintering temperature.

关键词： condensed state physis Nd-Fe-B magnets M-H loop squareness abnormal grains growth microstructure rare earths

Research on the Construction Characteristics of Stone-Built Folk Houses in Jiarong Tibetan Area <br/>—Take the Stone-Built Houses in Xisuo Village as an Example

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World Journal of Engineering and Technology 2020年第3期8卷 485-504页

作者： Xinwen Hou Bin Cheng School of Civil Engineering and Architecture Southwest University of Science and Technology Mianyang China

The Jiarong Tibetan traditional residence is a characteristic regional architecture, located in a high-intensity, high-altitude and cold area, with geographic identification, and is a typical representative of this ethnic group. It has also become an important tourist destination and has important research value. The research used the methods of field survey surveying and mapping to conduct field survey and surveying on 20 buildings in Xisuo Village, a traditional village in the Jiarong Tibetan area. Measure building plans, elevations, and building sections, and collect measurement data for statistical analysis. The results show that the average total height of the building is 10.08 m, the average total building span is 12.44 m, the average total depth is 10.87 m, and the squareness is 0.87. The square shape of the building is more in line with the seismic requirements of high-intensity areas and the local terrain environment. The maximum window-wall ratio in the building is 0.18 south for the second floor, and 0.025 west for the first floor. Smaller window-to- wall ratios have better adaptability to high-altitude cold areas. The height of the building beam section is generally from 0.17 m to 0.32 m, and the average Beam span-depth ratio is 0.10. The building space construction has a good match with the properties of wood materials. These conclusions quantitatively analyze the characteristics of stone-built houses in high-intensity, high-altitude and cold areas, supplement the research on ethnic regional architecture, and provide materials and references for the design, repair and update of related buildings.

关键词： Jiarong Tibetan squareness Window-Wall Ratio Space Construction Beam Span-Depth Ratio