Structural and Magnetic Properties of Sm(CobalFe0.1Ni0.12Zr0.04B0.04)7.5 Melt Spun Ribbons

Materials Science Forum ◽

10.4028/www.scientific.net/msf.636-637.404 ◽

2010 ◽

Vol 636-637 ◽

pp. 404-410

Author(s):

Sofoklis S. Makridis

Keyword(s):

Magnetic Properties ◽

Hysteresis Loops ◽

Secondary Phase ◽

Maximum Energy ◽

Tem Analysis ◽

Energy Product ◽

Average Grain Size ◽

Melt Spun ◽

Melt Spun Ribbons ◽

Structural And Magnetic Properties

We have investigated the structural and magnetic properties of Sm(Co0.70Fe0.1Ni0.12Zr0.04B0.04)7.5 melt spun ribbons. The arc-melted bulk samples have been used to obtain ribbons at 37 up to 55 m/sec while annealing has been performed in argon atmosphere for 30-75 min at 600-870 oC. In as-spun ribbons the hexagonal SmCo7 (TbCu7-type of structure) of crystal structure has been determined from x-ray diffraction patterns, while fcc-Co has been identified as a secondary phase. After annealing, the 1:7 phase of the as-spun ribbons transforms into 2:17 and 1:5 phases. TEM analysis shows a homogeneous nanocrystalline microstructure with average grain size of 30-80 nm. Coercivity values of 15-27 kOe are obtained from hysteresis loops traced at non-saturating fields. The coercivity decreases as temperature increases, but it is high enough to maintain values higher than 5 kOe at 380 oC. The maximum energy product at room temperature increases, as high as 7.2 MGOe, for melt-spun ribbons produced at higher wheel speed.

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Structural and magnetic properties of Nd–(Fe,M)–(C,B) melt-spun ribbons

Journal of Alloys and Compounds ◽

10.1016/s0925-8388(00)00740-4 ◽

2000 ◽

Vol 305 (1-2) ◽

pp. 290-297 ◽

Cited By ~ 9

Author(s):

N Hayashi ◽

M Daniil ◽

Y Zhang ◽

G.C Hadjipanayis

Keyword(s):

Magnetic Properties ◽

Melt Spun ◽

Melt Spun Ribbons ◽

Structural And Magnetic Properties

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Structural and magnetic properties of Nd60Fe30−xCoxAl10 melt-spun ribbons

Journal of Applied Physics ◽

10.1063/1.1541638 ◽

2003 ◽

Vol 93 (10) ◽

pp. 6930-6932 ◽

Cited By ~ 3

Author(s):

Z. G. Sun ◽

W. Löser ◽

J. Eckert ◽

K.-H. Müller ◽

L. Schultz ◽

...

Keyword(s):

Magnetic Properties ◽

Melt Spun ◽

Melt Spun Ribbons ◽

Structural And Magnetic Properties

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New YDy-Based R2(Fe,Co)14B Melt-Spun Magnets (R=Y+Dy+Nd)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.2155 ◽

2005 ◽

Vol 475-479 ◽

pp. 2155-2160 ◽

Cited By ~ 13

Author(s):

W. Tang ◽

K.W. Dennis ◽

Matthew J. Kramer ◽

I.E. Anderson ◽

R.W. McCallum

Keyword(s):

Magnetic Properties ◽

High Temperature ◽

Temperature Coefficient ◽

Temperature Stability ◽

Maximum Energy ◽

Maximum Energy Product ◽

Energy Product ◽

Optimal Sample ◽

Melt Spun ◽

Nd Substitution

The effects of the ratio of Y to Dy as well as the effect of Nd and Co substitutions on magnetic properties in [Ndx(YDy)0.5(1-x)]2.2Fe14-yCoyB ribbons melt-spun at 22 m/s have been systematically studied. (Y1-zDyz)2.2Fe14B ribbons with a ratio z of 0.25 or 0.5 simultaneously obtains a smaller temperature coefficient of remanence (α ) and coervicity (β ) which are much smaller than those of Nd-based Nd2Fe14B ribbons. In [Ndx(YDy)0.5(1-x)]2.2Fe14-yCoyB ribbons, Nd substitution (x=0 to 0.8) can improve the maximum energy product (BH)max of annealed ribbons but degrades the temperature stability of the magnetic properties. The ribbons with x=0.4 and y=0 yield a (BH)max of 8.7 MGOe. For these ribbons, the α and β are -0.07 and -0.31 %/°C in the temperature range of 27 to 127°C, respectively. Increasing Co (x) from 0 to 3, slightly decreases coercivity Hcj from 21.5 to 16.3 kOe, but keeps the (BH)max in the range of 8.6 to 10.2 MGOe. The optimal sample with x=0.5 and y=1.5 obtains a (BH)max of 10.2 and 5.0 MGOe at 27 and 250°C, respectively. Its α and β are -0.11 and -0.30 %/°C, respectively. These results show that studied ribbons are very promising to develop into high temperature isotropic bonded magnets capable of operating at or above 180°C.

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Development of a High-Performance-Ferrite Magnet Fabrication Process without Sintering Additives

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2021.59.8.551 ◽

2021 ◽

Vol 59 (8) ◽

pp. 551-559

Author(s):

Pyeong-Yeol Yu ◽

Min-Ho Kim ◽

Young-Min Kang

Keyword(s):

Magnetic Properties ◽

Saturation Magnetization ◽

High Performance ◽

Secondary Phase ◽

Batch Process ◽

Maximum Energy ◽

Magnetic Flux Density ◽

Sintering Additives ◽

Energy Product ◽

Hard Magnetic Properties

Sintered M-type hexaferrites with the chemical formula of Sr0.3Ca0.4La0.3Fe9.8Co0.2-xMnxSi0.135O19-d (x = 0, 0.05, 0.1, 0.2) and Sr0.3Ca0.4La0.3Fe9.8-yCo0.2MnySi0.135O19-d (y = 0.05, 0.1, 0.2) were prepared by conventional solid station reaction routes. A high sintering density of more than 95% of the theoretical density was achieved in all hexaferrite samples when calcination was carried out at 1100 oC for 4 h, followed by sintering at 1230-1250 oC for 2 h without the use of sintering additives. High saturation magnetization and coercivity were achieved simultaneously at the x = 0.05 composition, where Mn replaces part of the Co. The secondary phase Fe2O3 generated by the initial addition of SiO2 was gradually reduced when the Fe contented was decreased in the Sr0.3Ca0.4La0.3Fe9.8-zCo0.15Mn0.05Si0.135O19-d samples, and a single M-type hexaferrite phase was confirmed in the Sr0.3Ca0.4La0.3Fe8.3Co0.15Mn0.05Si0.135O19-d (z = 1.5) sample, which also exhibited optimized hard magnetic properties, with a saturation magnetization of 4581 G and coercivity of 4771 Oe. Anisotropic sintered magnets were fabricated using the optimized composition, and showed excellent hard magnetic properties, with a remanent magnetic flux density of 4400 G and intrinsic coercivity of 4118 Oe, and a maximum energy product of 4.72 M·G·Oe. This result is very promising because high magnet performance can be achieved with a single batch process without the need for sintering additives during the process.

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Preparation of Anisotropic Nd-Lean Nd-Fe-B Magnets with Improved Coercivity

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1675 ◽

2017 ◽

Vol 898 ◽

pp. 1675-1680

Author(s):

Qian Shen ◽

Yi Long Ma ◽

Xue Guo Yin ◽

Tao Zhou

Keyword(s):

Magnetic Properties ◽

Grain Boundary ◽

Grain Growth ◽

The Other ◽

Zn Diffusion ◽

Energy Product ◽

Initial Stage ◽

The Press ◽

Melt Spun ◽

Melt Spun Ribbons

Anisotropic bulk nanocrystal Nd-lean Nd-Fe-B magnets were prepared by hot-pressing the mixture of Nd11.5Fe81.5Nb1B6 melt-spun ribbons and pure Zn powder and subsequent hot-deforming. The effects of deformation on the magnetic properties and microstructure were also studied. The magnetic properties increased significantly for hot-deformed (HD) samples due to the formation of good c-axis texture with increasing deformation. The remanence Mr and maximal energy product (BH)m increased and reached their maximal values at 65% deformation due to the increasing orientation. On the other hand, the grains increased and were elongated normal to the press direction gradually with increasing deformation. The variation trend was similar to that of traditional Nd-Fe-B magnets. However, there was an obvious improvement for coercivity in the initial stage of hot-deformation resulting from the adequate Zn diffusion into grain-boundary. When the deformation was larger than 65%, the magnetic properties were deteriorated due to abnormal grain growth. In order to improve further the coercivity Hci, the samples with Dy addition were prepared. The coercivity of 12300 Oe could be obtained for anisotropic bulk Nd9.5Dy2Fe81.5Nb1B6.

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Structural and magnetic properties of Nd-Fe-Mo-(N) melt-spun ribbons with ThMn12 structure

Acta Materialia ◽

10.1016/j.actamat.2020.05.045 ◽

2020 ◽

Vol 195 ◽

pp. 519-526 ◽

Cited By ~ 1

Author(s):

A. Aubert ◽

R. Madugundo ◽

A.M. Schönhöbel ◽

D. Salazar ◽

J.S. Garitaonandia ◽

...

Keyword(s):

Magnetic Properties ◽

Melt Spun ◽

Melt Spun Ribbons ◽

Structural And Magnetic Properties

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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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