Multiphase microstructure and magnetic properties of high performance Nd-Fe-B ribbons with multielement addition

Ce14Fe78Co2B6 nanopowders with hard-magnetic properties have been successfully prepared by ball milling at low temperatures in liquid nitrogen. The morphology, structure, and magnetic properties of Ce14Fe78Co2B6 powders have been investigated using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry, respectively. It was found that powder ball milling at low temperature in liquid nitrogen, has the advantage that the oxidation of powders is inhibited and the particles rapidly reach nanometric dimensions. In comparison to the Ce14Fe78Co2B6 powders prepared by ball milling at room temperature, the powders milled at low temperature present a more uniform particle size and no rare-earth oxides, which leads thus to remarkable magnetic properties. The nanocrystalline Ce14Fe78Co2B6 powders with optimum characteristics, prepared at low temperature, have the size of 153 nm or less, present a coercivity of 5.1 kOe, and a saturation magnetization of 113 emu/g after milling for 6 h at low temperature. Low temperature milling may become a promising technique for the fabrication of high performance powders used for permanent magnets preparation.

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Prepared and Study of Low Cost and High Performance Nanocomposite (Nd,Dy,Pr)-(Fe,Nb,Zr)-B/α-Fe

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.647.777 ◽

2013 ◽

Vol 647 ◽

pp. 777-782

Author(s):

Jin Jiang Hu ◽

Chen Pu Li ◽

Chao Liu

Keyword(s):

Magnetic Properties ◽

High Performance ◽

Magnetic Phase ◽

Low Cost ◽

Wheel Speed ◽

Interaction Domain ◽

Axis Parallel ◽

Exchange Coupling Interaction ◽

Strong Exchange ◽

Microstructure And Magnetic Properties

The microstructure and magnetic properties of melt-spun nanocomposite (Nd, Dy, Pr)-(Fe,Nb,Zr)-B /α-Fe ribbons have been investigated by XRD, SPM and VSM. The ribbons were prepared at a wheel speed range of 10-30 m/s. The multigrain domain or interaction domain was observed in the samples prepared at 20 m/s wheel speed. The easy magnetized direction c-axis parallel to the ribbon plane for the sample prepared at the wheel speed of 20m/s. The average gain size in this sample is about 18nm and the sample consists of hard magnetic phase (Nd, Dy, Pr) 2(Fe,Nb,Zr)14B and sofe magnetic phase α-Fe, there is strong exchange-coupling interaction between them. The magnetic properties obtained are Br=1.28T，Hci= 504.2kA•m-1，(BH)max= 157.8 kJ•m-3，Mr/Ms =0.76.

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Phase Formation, Microstructure, and Magnetic Properties of Nd14.5Fe79.3B6.2 Melt-Spun Ribbons with Different Ce and Y Substitutions

Materials ◽

10.3390/ma14143992 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3992

Author(s):

Qingjin Ke ◽

Feilong Dai ◽

Shengxi Li ◽

Maohua Rong ◽

Qingrong Yao ◽

...

Keyword(s):

Magnetic Properties ◽

Phase Formation ◽

High Performance ◽

Magnetic Energy ◽

Co Substitution ◽

Energy Product ◽

Melt Spun ◽

Low Costs ◽

Melt Spun Ribbons ◽

Microstructure And Magnetic Properties

Phase formation and microstructure of (Nd1-2xCexYx)14.5Fe79.3B6.2 (x = 0.05, 0.10, 0.15, 0.20, 0.25) alloys were studied experimentally. The results reveal that (Nd1-2xCexYx)14.5Fe79.3B6.2 annealed alloys show (NdCeY)2Fe14B phase with the tetragonal Nd2Fe14B-typed structure (space group P42/mnm) and rich-RE (α-Nd) phase, while (Nd1-2xCexYx)14.5Fe79.3B6.2 ribbons prepared by melt-spun technology are composed of (NdCeY)2Fe14B phase, α-Nd phase and α-Fe phase, except for the ribbon with x = 0.25, which consists of additional CeFe2 phase. On the other hand, magnetic properties of (Nd1-2xCexYx)14.5Fe79.3B6.2 melt-spun ribbons were measured by a vibrating sample magnetometer (VSM). The measured results show that the remanence (Br) and the coercivity (Hcj) of the melt-spun ribbons decrease with the increase of Ce and Y substitutions, while the maximum magnetic energy product ((BH)max) of the ribbons decreases and then increases. The tendency of magnetic properties of the ribbons could result from the co-substitution of Ce and Y for Nd in Nd2Fe14B phase and different phase constitutions. It was found that the Hcj of the ribbon with x = 0.20 is relatively high to be 9.01 kOe, while the (BH)max of the ribbon with x = 0.25 still reaches to be 9.06 MGOe. It suggests that magnetic properties of Nd-Fe-B ribbons with Ce and Y co-substitution could be tunable through alloy composition and phase formation to fabricate novel Nd-Fe-B magnets with low costs and high performance.

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Microstructure and Magnetic Properties of Nd4.5Fe(76.5-x)B18.5Cu0.5Zrx Nanocomposite Permanent Magnetic Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.121-123.1277 ◽

2007 ◽

Vol 121-123 ◽

pp. 1277-1280 ◽

Cited By ~ 1

Author(s):

Y. Qiao ◽

Mao Cai Zhang ◽

J. Zhu

Keyword(s):

Grain Size ◽

Magnetic Properties ◽

Exchange Coupling ◽

High Performance ◽

Magnetic Phase ◽

Soft Magnetic ◽

Phase Component ◽

Average Grain Size ◽

The Difference ◽

Microstructure And Magnetic Properties

Nanocomposite Nd2Fe14B/Fe3B magnetic materials with high performance have been obtained by crystallizing over-quenched ribbons. The effect of addition element of Cu and Zr on the phase component, microstructure and magnetic properties of Nd4.5Fe（76.5-x）B18.5Cu0.5Zrx (x= 0.4, 0.5, 1.5, 2.0, 3.0, 4.0) has been systematically investigated. The average grain size of Nd2Fe14B phase and Fe3B phase for the different compositions were calculated from X-day diffraction pattern, which are in accordance with TEM micrographs. For the Nd4.5Fe77B18.5 ribbons, the average grain size of Nd2Fe14B and Fe3B were 34.2 nm and 51.7 nm, and for the Nd4.5Fe76.3B18.5Cu0.5Zr0.4 ribbons, they were only 36.5 nm and 37.1 nm, respectively. It has been found that the additions of Cu and Zr cause the reduction of the difference of grain size between the hard magnetic phase and the soft magnetic phase, that increase the exchange coupling between them. Therefore, it would lead to the magnetic properties improvement. It has been determined that Nd4.5Fe76.3B18.5Cu0.5Zr0.4 was the optimal composition, and the optimal magnetic properties were: Br= 1.204 T, Hci= 271 kA/m, and (BH)max =111.2 kJ/m3.

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Microstructure and Magnetic Properties of Barium Hexaferrite Produced by Sol Gel Auto Combustion for Radar Absorber Material (RAM) Application

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.493.656 ◽

2014 ◽

Vol 493 ◽

pp. 656-660 ◽

Cited By ~ 3

Author(s):

Widyastuti ◽

Endah Kharismawati ◽

M. Zainuri ◽

Hosta Ardhyananta

Keyword(s):

Magnetic Properties ◽

High Performance ◽

Sol Gel ◽

Barium Hexaferrite ◽

Hexagonal Structure ◽

X Ray Diffraction ◽

Absorber Material ◽

Auto Combustion ◽

Stirring Time ◽

Microstructure And Magnetic Properties

Barium hexaferrite (BaFe12O19) with hexagonal structure has been known as the high performance magnetic for Radar Absorber Material (RAM). Barium hexaferrite (BaM) was synthesized by sol gel auto combustion to get an homogeneous nanoparticle of BaM. Barium hexaferrites obtained from solution mixture between barium nitrate and ferri nitrate nonahidrat with precipitation of ion barium (Ba2 +) and ferri (Fe3 +) by solution of sodium hydroxide. Sample prepared with mol ratio of Fe / Ba 11 then added ammoniac in order that pH varies become 7,5; 9; and 11. Citric acid added in order that happen process of combustion. The stirring time was varieties by 1, 2, 3 hours. The effect of pH, stirring time, microstructure, phase,and magnetic properties were investigated using X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and a vibrating sample magnetometer (VSM). The results showed that the highest coercivity was 0.6 Tesla and the smallest crystal size 414.409 nm was obtained for pH 7.5 and stirring time 2 hours. The largest magnetic saturation 55.54 emu /g was reached for pH 7.5 with stirring time 1 hour

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