scholarly journals Preparation of Sm−Fe−N Bulk Magnets with High Maximum Energy Products

2020 ◽  
Vol 44 (3) ◽  
pp. 64-69 ◽  
Author(s):  
R. Matsunami ◽  
M. Matsuura ◽  
N. Tezuka ◽  
S. Sugimoto
Keyword(s):  
Maximum Energy ◽  
High Maximum ◽  
Energy Products

Influence of Additional Micro-Sized Particles of Dy–Nd–Cu–Al on Magnetic Properties of Sintered Nd–Fe–B Magnets

2021 ◽  
Vol 21 (4) ◽  
pp. 2558-2562
Author(s):  
Pham Thi Thanh ◽  
Dinh Thi Kim Oanh ◽  
Nguyen Hai Yen ◽  
Nguyen Huy Dan
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
Weight Fraction ◽  
Maximum Energy ◽  
Vacuum Sintering ◽  
Magnetic Parameters ◽  
Maximum Value ◽  
High Maximum ◽  
Milling Method ◽  
Energy Products

In this work, we investigated the influence of concentration of the additional micro-sized particles of Dy40Nd30Al30 and Nd40Cu30Al30 on magnetic properties of the sintered Nd16.5Fe77B6.5 magnets. The additional particles with size in the range of 1–3 μm were prepared by ball milling method and then mixed into micrometer Nd16.5Fe77B6.5 master powder with different weight fractions before magnetic anisotropic pressing, vacuum sintering and annealing. The results show that the coercivity of the sintered Nd–Fe–B magnets can be improved considerably by introducing additional particles to the grain boundaries. The improvement of the coercivity Hc of the magnets is clearly dependent on the composition and concentration of the additional microparticles. The Hc increases linearly from 8.5 kOe to 17 kOe with increasing the weight fraction of the Dy40Nd30Al30 microparticles from 0 to 5%. Meanwhile, the coercivity of the magnet reaches a maximum value of 11.7 kOe with 4 wt% addition of Nd40Cu30Al30. The quite high maximum energy products, (BH)max > 30 MGOe, were also obtained for the magnets added with the microparticles. The obtained hard magnetic parameters of the magnets can be applied in practice.

Nanocrystalline and Nanostructured High-Performance Permanent Magnets

2001 ◽  
Vol 674 ◽  
Author(s):  
D. Goll ◽  
W. Sigle ◽  
G.C. Hadjipanayis ◽  
H. Kronmüller
Keyword(s):  
Magnetic Properties ◽  
High Performance ◽  
Permanent Magnets ◽  
Maximum Energy ◽  
High Quality ◽  
Hardening Mechanism ◽  
Temperature Dependences ◽  
Complex Correlation ◽  
Energy Products

ABSTRACTThe rather complex correlation between the microstructure and the magnetic properties is demonstrated for two types of high-quality RE-TM permanent magnets (pms), namely nanocrystalline RE2Fe14B (RE = Nd,Pr) and nanostructured Sm2(Co,Cu,Fe,Zr)17 pms. The detailed analysis of this correlation for both pm materials leads to a quantitative comprehension of the hardening mechanism enabling the optimization of their magnetic properties and temperature dependences. In the case of RE2Fe14B, isotropic bonded pms are fabricated showing maximum energy products in the order of 90 kJ/m3. In the case of Sm2(Co,Cu,Fe,Zr)17, magnets with excellent high-temperature magnetic properties are tailored. Hereby, the investigations in addition provide important clues to the evolution of the characteristic microstructural and magnetic properties and to the role of the involved elements.

Study on the Nanostructure and Magnetic Properties of NdFeNbB Permanent Magnets

2010 ◽  
Vol 638-642 ◽  
pp. 1749-1754
Author(s):  
X.F. Wang ◽  
X.Y. Chen ◽  
Z.L. Jiang ◽  
Y. Chen ◽  
H.M. Chen
Keyword(s):  
Exchange Coupling ◽  
Permanent Magnets ◽  
Coupling Effect ◽  
Maximum Energy ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
Maximum Energy Product ◽  
Energy Product ◽  
High Maximum ◽  
Intrinsic Coercivity

Nd2Fe14B/-Fe nanocomposite permanent magnet contains the hard and soft magnetic phases, Nd2Fe14B and -Fe respectively. An exchange coupling effect exists between the two magnetic phases. The effect of alloying element Nb on its nanostructure and properties have been studied. Adding Nb to the alloy is effective to refine grains, a relatively small grain size causes a high intrinsic coercivity, remanence and therefore a high maximum energy product, (BH)max. MFM (Magnetic Force Microscope) was used to observe the magnetic micro-domain structure in the nanophase alloys. The length of the magnetic contrast shows a significant dependence on the microstructure and phase constitution, and the longer length is correspond with the larger exchange coupling effect between the soft and hard magnetic phases.

Microstructure of high-energy product Fe-Nd-B magnequench ribbons

1986 ◽  
Vol 44 ◽  
pp. 826-827
Author(s):  
Y. L. Chen
Keyword(s):  
Anisotropy Field ◽  
Microstructural Characterization ◽  
High Energy ◽  
Maximum Energy ◽  
Maximum Energy Product ◽  
Energy Product ◽  
High Anisotropy ◽  
Energy Products ◽  
Very High

Melt-spun Fe-Nd-B MAGNEQUENCH® ribbons have been produced by Croat et al. with energy products in excess of 10 MG.Oe using a relatively narrow window of composition and quenching speed. The hard magnetic phase has subsequently been identified as the Nd2Fe14B compound which has a very high anisotropy field. The microstructure of the MAGNEQUENCH® ribbon which has a maximum energy product of 14.1 MG•0e was found to consist of equiaxed Nd2Fe14B grains surrounded by a very thin intergranular film. This paper presents the results of some of our earlv work on the microstructural characterization of high energy product MAGNEQUENCH® ribbons having nominal compositions of Nd13Fe82.6B4.4 and Nd15Fe79.9B5.1. The purpose of this investigation was to characterize the microstructures of various MAGNEQUENCH® ribbons for correlation with their magnetic properties.

Research on Magnetic Properties of Nd2Fe14B/α-Fe/Nd2Fe14B Exchange-Coupled Trilayer Films

2011 ◽  
Vol 84-85 ◽  
pp. 567-571
Author(s):  
Min Gang Zhang ◽  
Li Li Yang ◽  
Yi Chao Zhao ◽  
Jia Zhang ◽  
Gang Sun
Keyword(s):  
Exchange Coupling ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Maximum Energy ◽  
Soft Magnetic ◽  
Coupling Region ◽  
Magnetic Hysteresis Loops ◽  
Complete Exchange ◽  
Energy Products ◽  
The Relationship

The magnetic hysteresis loops of Nd2Fe14B/α-Fe/Nd2Fe14B exchange-coupling trilayer film are simulated by micromagnetic theory, and the relationship between remanence, coercivity, energy products and soft magnetic thickness are discussed in detail. The results show that the hysteresis loops is rectangle and the trilayer films are in complete exchange-coupling region when the soft magnetic thickness is below the critical point(5nm); With the increase of the soft magnetic thickness, the coercivity of the trilayer films decreases monotonically. Maximum energy products are obtained when the soft magnetic thickness is 5nm.

Melt-Spun Permanent Magnet Alloy with Enhanced Isotropic Remanence

1986 ◽  
Vol 80 ◽  
Author(s):  
A. M. Kadin ◽  
R. W. McCallum ◽  
G. B. Clemente ◽  
J. E. Keem
Keyword(s):  
Permanent Magnet ◽  
High Performance ◽  
Melt Spinning ◽  
Maximum Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Performance ◽  
Magnet Alloy ◽  
Energy Products ◽  
Permanent Magnet Alloy

AbstractRapid solidification onto a copper quench surface (melt-spinning) has been used to fabricate a high-performance permanent magnet alloy (Ovonic Hi-Rem™) based on the Nd-Fe-B class of materials. Crucial idditions of alloying elements are combined with careful control over quench parameters to yield a random assembly of microcrystallites, with macrosconically isotropic magnetic properties including values of remanent induction that can exceed 10 kG and maximum energy products greater than 20 MGOe. These values exceed those expected from conventional randomly oriented magnets. The enhanced magnetic performance is related to results of x-ray diffraction and electron microscopy.

scholarly journals Coercive force mechanism in Nd-Fe-B nanocrystalline magnet investigated by SANS

2014 ◽  
Vol 70 (a1) ◽  
pp. C146-C146
Author(s):  
Tetsuro Ueno ◽  
Kotaro Saito ◽  
Masao Yano ◽  
Masashi Harada ◽  
Tetsuya Shoji ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Coercive Force ◽  
Saturation Magnetization ◽  
High Efficiency ◽  
Intensity Variation ◽  
Maximum Energy ◽  
Maximum Energy Product ◽  
Energy Product ◽  
High Maximum

Permanent magnet material with high maximum energy product is demanded for industrial applications such as high-efficiency motors for hybrid and electric vehicles. Maximum energy product depends on the coercive force and the saturation magnetization. In order to achieve the high maximum energy product, current Nd-Fe-B magnets are doped with heavy rare-earth element Dy to enhance the coercive force at the expense of reducing the saturation magnetization. Viewed from another side, a supply of Dy is highly concerned because of the inequitable distribution of rare-earth resources on the Earth. Therefore, development of a Dy-free Nd-Fe-B magnet is desired. In this context, we have fabricated the Dy-free Nd-Fe-B nanocrystalline magnet and performed the small-angle neutron scattering (SANS) experiment to reveal the mechanism of its coercive force. Hot-deformed Nd-Fe-B nanocrystalline magnets with and without the diffusion process of Pr-Cu eutectic alloy were prepared [1]. Coercive forces were 1.46 T and 2.64 T for as-deformed and Pr-Cu infiltrated sample, respectively. Magnetic field dependent SANS experiment was performed to observe the magnetization reversal process. The reversal magnetic field was swept from 0 T to 5 T. SANS intensities exhibit maxima around the coercive force for both as-deformed and infiltrated sample, which indicates the evolution of the magnetic domain structure. In addition, suppressed intensity variation in infiltrated sample compared to that in as-deformed sample indicates the magnetic isolation of Nd2Fe14B grains, which is responsible for the high coercive force. We will compare the results for Pr-Cu infiltrated sample with Nd-Cu infiltrated one [1]. This work was supported by the Elements Strategy Initiative Center for Magnetic Materials under the outsourcing project of the MEXT, Japan. We thank HZB for the allocation of neutron beamtime (Proposal No. MAT-04-2110). The sample preparation was performed under the MagHEM project.

Hot-deformed Nd-Fe-B magnets fabricated by dynamic loading with a high maximum energy product

2016 ◽  
Vol 73 ◽  
pp. 67-71 ◽  
Author(s):  
Tieqiao Zhang ◽  
Fugang Chen ◽  
Yan Zheng ◽  
Hongyuan Wen ◽  
Jing Wang ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Maximum Energy ◽  
Maximum Energy Product ◽  
Energy Product ◽  
High Maximum

The fabrication and characterization of MnAl/FeCo composite thin films with enhanced maximum energy products

2017 ◽  
Vol 197 ◽  
pp. 8-11 ◽  
Author(s):  
Rui Dang ◽  
Xiangrong Ma ◽  
Jieying Liu ◽  
Yuxin Zhang ◽  
Sujin Qian
Keyword(s):  
Thin Films ◽  
Maximum Energy ◽  
Composite Thin Films ◽  
Fabrication And Characterization ◽  
Energy Products

The magnetic properties and domain structures of nanocrystalline Ce–Fe–B magnets with enhanced maximum energy products

2018 ◽  
Vol 32 (29) ◽  
pp. 1850319 ◽  
Author(s):  
Minxiang Pan ◽  
Hui Xu ◽  
Zhong Li ◽  
Xiaohua Tan ◽  
Xueling Hou ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Exchange Interactions ◽  
Maximum Energy ◽  
Annealed Sample ◽  
Domain Structures ◽  
Heat Treated ◽  
Energy Products ◽  
Rapidly Solidified

Optimizing of alloy composition and heat-treatment for rapidly solidified Ce–Fe–B magnets can lead nanocrystalline products with enhanced magnetic properties. In this work, the magnetic properties and domain structures of the nanocrystalline Ce[Formula: see text]Fe[Formula: see text]Co1Zr[Formula: see text]B6 have been investigated. The results show that hard Ce2Fe[Formula: see text]B magnetic phase and paramagnetic CeFe2 phase are crystallized for the heat treated alloys, while the volume fraction and grain size of Ce2Fe[Formula: see text]B and CeFe2 phases change significantly with the increase of annealing temperature. The enhanced coercivity H[Formula: see text] of 6.32 kOe and maximum energy products (BH)[Formula: see text] of 5.52 MGOe have been observed for the Ce[Formula: see text]Fe[Formula: see text]Co1Zr[Formula: see text]B6 ribbons at the optimal annealing temperature of 520[Formula: see text]C and 580[Formula: see text]C, respectively. Meanwhile, the magnetization reversal behaviors and the nucleation field of the annealed sample were discussed in detail. The domain structures analysis provides more information on the characteristic of the domain width W as well as the exchange interactions.

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