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.

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

Synthesis and Characterization of Electromagnetic Material Based On Composite of Barium M-Ferrite and Zinc Oxide

2018 ◽  
pp. 78-82
Author(s):  
Verryon Harahap ◽  
Syahrul Humaidi ◽  
Perdamean Sebayang
Keyword(s):  
Zinc Oxide ◽  
Magnetic Properties ◽  
High Energy ◽  
Lattice Parameter ◽  
Milling Process ◽  
Raw Material ◽  
Wet Milling ◽  
Hexagonal Crystal ◽  
Milling Method ◽  
Energy Products

The making of composites BaFe12O19/ZnO has been done with Wet Milling method used media toluene. Barium M-Ferrit as a matrix and Zinc Oxide as a filler used as the main raw material for composite manufacturing. The milling process of Barium M-Ferrit was done for 12 hours using the High Energy Milling (HEM). Furthermore, the calcination process used furnace at 900 ° C for 4 hours. While Zinc Oxide is milled for 3 hours and calcined at a temperature of 500 oC for 3 hours. The results of Barium M-Ferrit and zinc Oxide mixed using wet milling touluene media for 15 minutes and dried for 1 hour at 200 oC. X-ray diffraction (XRD) showed that BaFe12O19 as a matrix and ZnO as filler with hexagonal crystal structure was formed and the peak showed a single phase, where each BaFe12O19 lattice parameter a = 5.8930 Å, c = 23.1940 Å and ZnO lattice parameter a = 3.2533 Å, c = 5.2073 Å. Characterization Vibrating Sample Magnetometer (VSM) obtained the value of magnetic properties BaFe12O19 powder (matrix) obtained (Ms) magnetic saturation 54.03 emu/g, (Mr) magnet remanent 33.06 emu/g, (Hcj) coercivity 2943 Oe and (BHmax) product energy 190 kGOe and Zinc Oxide as filler values (Ms) magnet saturation 7.84 emu / g, (Mr) magnet remanent 1.27 emu/g, (Hcj) coercivity 152.4 Oe and (BHmax) energy products 10 kGOe. The results of XRD on 50% mass of composites ZnO additions using match software have two phases, namely the presence of ZnO and BaFe12O19 phases which indicate that heterogeneous structures with hexagonal crystal structures. Composite magnetic properties obtained by adding 50% mass of ZnO were (Mr) magnet 39.40 emu/ g, coercivity 2728 Oe, (BHmax) product energy 110 kGOe and for composites 75% mass addition ZnO remanent 39.36 emu/g with coefficient of 1365 Oe and ( BHmax) product energy was 60 kGOe.

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.

Sintering Sm2Fe17 Prior to Nitrogenation

2008 ◽  
Vol 591-593 ◽  
pp. 75-79 ◽  
Author(s):  
R. Bahr ◽  
R. Hesse ◽  
J.C. Boareto ◽  
Paulo A.P. Wendhausen
Keyword(s):  
Magnetic Properties ◽  
Casting Process ◽  
Mass Gain ◽  
Maximum Energy ◽  
X Ray Diffraction ◽  
Initial Composition ◽  
X Ray ◽  
Hard Magnets ◽  
Energy Products ◽  
Hard Magnetic Properties

The sintering of Sm2Fe17 compound prior to the nitrogenation process is studied as an alternative process to produce dense Sm2Fe17N3 hard magnets with higher maximum energy products (BH)max than conventional polymer bonded magnets. In order to optimize sintering and nitrogenation processes, powders made from alloys, with different compositions, in the as-cast as well in the as-homogenized state were used. It could be shown that the amount of α-Fe, formed in the casting process, was reduced during sintering and that Sm selective loss is restricted to the surface up to a depth of 100 +m. Moreover the density of the sintered samples was not much affected by the initial composition or by the prior homogenization of the alloys. Although the nitrogenation process was successful in producing the Sm2Fe17N3 as proved by the mass gain, magnetic properties measurements and X-Ray diffraction, the hard magnetic properties were much lower than expected, indicating that other variables, which are discussed in the text, must be considered.

Structure, magnetic properties and Mössbauer spectra of La0.67Sr0.33FexMn1 − xO3 manganites oxide prepared by mechanical ball milling method

2012 ◽  
Vol 211 (1-3) ◽  
pp. 153-164 ◽  
Author(s):  
Wajdi Chérif ◽  
Mohamed Ellouze ◽  
Abdel-Fatah Lehlooh ◽  
Sami H. Mahmood ◽  
Foued Elhalouani
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra ◽  
Milling Method ◽  
Mechanical Ball Milling

Ball milling effect on structural and magnetic properties of Ni–Mn–Ga ferromagnetic nanoparticles

2011 ◽  
Vol 83 (11) ◽  
pp. 2071-2077 ◽  
Author(s):  
Kaliyan Vallal Peruman ◽  
Manickam Mahendran
Keyword(s):  
Magnetic Properties ◽  
Internal Stress ◽  
Ball Milling ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Nano Crystalline ◽  
Milling Method ◽  
Milling Duration ◽  
Average Internal Stress ◽  
Hard Magnetic Properties

The off-stoichiometric Ni2MnGa ferromagnetic alloys are one of the active materials that are of great interest when they are ball milled into nanopowder. These powders are prospective materials for nanosystem applications. However, the properties of the nano-crystalline Ni–Mn–Ga alloys depend strongly on their structure and internal stress, which develop during the milling process. Ni–Mn–Ga nanoparticles were prepared by ball-milling method, and characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) techniques. The powders are found to be a disordered mixture structure of austenite and martensite. We calculated that an average internal stress is 0.28 to 2.05 MPa stored in the distorted lattice due to milling. Reduction in particle sizes is accompanied by increase of the lattice strain level when the milling time increases. The VSM reveals that magnetic saturation and coercivity decrease with increase of the milling duration. This phenomenon causes deterioration in the hard magnetic properties.

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