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

2005 ◽  
Vol 475-479 ◽  
pp. 2155-2160 ◽  
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.

Effects of Magnetic Powder Loading on Mechanical Properties and Magnetic Properties of Natural Rubber

2006 ◽  
Vol 45 ◽  
pp. 1423-1428
Author(s):  
Somsak Woramongconchai ◽  
Chatchawan Lohitvisat ◽  
Aree Wichainchai
Keyword(s):  
Mechanical Properties ◽  
Magnetic Properties ◽  
Coercive Force ◽  
Natural Rubber ◽  
Barium Ferrite ◽  
Maximum Energy ◽  
Magnetic Powder ◽  
Elongation At Break ◽  
Maximum Energy Product ◽  
Energy Product

The effect of magnetic powders and powders loading on magnetic properties and mechanical properties of magnetic rubbers were studied. The natural rubber with magnetic powders, Barium ferrite, Neodymium iron boron, were used as starting materials to prepare magnetic rubbers. Barium ferrite (BaO.6F2O3) powders had been sintered at 1285 oC for 30 hours to improve its crystal structure. The physical properties of magnetic rubbers, residual flux density (Br), coercive force (Hc), maximum energy product (BHmax), hardness and density, had a trend to increase as enhancing magnetic powders loading. However, some properties such as, intrinsic coercive force (Hci), tensile strength and elongation at break, had a trend to decrease when the magnetic powder loading was increased. Magnetic properties of the anisotropic type, sintered powders, were higher than isotropic type, non-sintered powders, except the Hci because anisotropic magnetic rubber indicated crystal orientation in the same direction.

Effect of Dysprosium Content on the Magnetic Properties of Nanocrystalline (Pr0.25Nd0.75)10-xDyxFe82Co2B6 Alloys

2014 ◽  
Vol 789 ◽  
pp. 28-31 ◽  
Author(s):  
He Wei Ding ◽  
Chun Xiang Cui ◽  
Ji Bing Sun
Keyword(s):  
Magnetic Properties ◽  
Melt Spinning ◽  
Maximum Energy ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Intrinsic Coercivity ◽  
Electronic Microscope ◽  
Microstructure And Magnetic Properties

(Pr0.25Nd0.75)10-xDyxFe82Co2B6(x=0~0.3) ribbons were prepared by melt spinning at 25m/s and subsequent annealing. The effect of Dy content on the microstructure and magnetic properties of the ribbons has been investigated by X-ray diffractometer (XRD), scanning electronic microscope (SEM) and vibrating sample magnetometer (VSM). The magnetic properties related to the Dy content were characterized. Intrinsic coercivity of 598kA/m, remanence of 0.58T, and the maximum energy product (BH)max of 43kJ/m3 were achieved in (Pr0.25Nd0.75)9.8Dy0.2Fe82Co2B6 after annealing at 700°C for 10 minutes.

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

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.

scholarly journals Nanocrystalline Nd-Fe-B Alloys for Polymer-Bonded Magnets Production

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Aleksandar Grujić ◽  
Vladan Ćosović ◽  
Aleksandar Ćosović ◽  
Jasna Stajić-Trošić
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Magnetic Phase ◽  
Coupling Effect ◽  
Maximum Energy ◽  
Soft Magnetic ◽  
Nanocomposite Structure ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Composite Production

This study presents how different nanostructures of starting Nd-Fe-B particles have influence on magnetic properties of polymer-bonded Nd-Fe-B materials. Two types of nanocrystalline Nd-Fe-B alloys were used for polymer composite production by compression molding technique. The particles with low neodymium content (Nd-low) have nanocomposite structure with small exchange coupling effect between hard and soft magnetic phase. In other hand, practically monophase hard magnetic structure of Nd-Fe-B particles with stoichiometric neodymium content (Nd-stoich) shows improved magnetic properties. With increasing concentration of polymer matrix, the coercivity (Hcb), remanence (Br), and maximum energy product ((BH)max) decrease more prominenty for composites with stoichiometric Nd-Fe-B content.

Magnetic Domain Structure of Nanocrystalline Zr18-xHfxCo82 Ribbons: Effect of Hf

2013 ◽  
Vol 1557 ◽  
Author(s):  
Lanping Yue ◽  
I. A. Al-Omari ◽  
Wenyong Zhang ◽  
Ralph Skomski ◽  
D. J. Sellmyer
Keyword(s):  
Magnetic Properties ◽  
Domain Structure ◽  
Structure Refinement ◽  
Magnetic Domain ◽  
Maximum Energy ◽  
Magnetic Domain Structure ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Domain Structures ◽  
Rapidly Solidified

ABSTRACTThe effect of Hf on the permanent magnetism of nanocrystalline Zr18-xHfxCo82 ribbons (x = 0, 2, 4, and 6) was investigated by magnetic properties measurement and magnetic force microscopy (MFM). Emphasis is on the local magnetic domain structures in polycrystalline rapidly solidified Zr18-xHfxCo82 ribbons for four different samples with small fractions of Hf dopants (x ≤ 6). The investigation of the magnetic properties of the Zr18-xHfxCo82 ribbons revealed that all the samples under investigation are ferromagnetic at room temperature, and the corresponding MFM images show bright and dark contrast patterns with up-down magnetic domain structures. It is found that the saturation magnetization and the coercivity depend on Hf doping concentration x in the samples. For a sample with Hf concentration x = 4, the maximum energy product (BH)max value is 3.7 MGOe. The short magnetic correlation length of 131 nm and smallest root-mean-square phase shift value of 0.680 were observed for x = 4, which suggests the refinement of the magnetic domain structure due to weak intergranular exchange coupling in this sample. The above results indicate that suitable Hf addition is helpful for the magnetic domain structure refinement, the coecivity enhancement, and the energy-product improvement of this class of rare-earth-free nanocrystalline permanent-magnet materials.

ALNICO-V-7

Alloy Digest ◽  
1966 ◽  
Vol 15 (10) ◽  
Keyword(s):  
Magnetic Properties ◽  
Cast Alloy ◽  
Maximum Energy ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Iron Aluminum ◽  
Nickel Cobalt ◽  
Magnet Alloy ◽  
Engineering Company ◽  
Permanent Magnet Alloy

Abstract ALNICO V-7 is a heat treatable cast alloy of iron, aluminum, nickel, cobalt and copper. It is a permanent magnet alloy having directional magnetic properties and a maximum energy product of 7,500,000 gauss-oersteds. (Also known as ALNICO 5-7) This datasheet provides information on composition, physical properties, hardness, and tensile properties. Filing Code: Fe-29. Producer or source: Arnold Engineering Company.

Phase Structure and Magnetic Properties of Fe-Nb-B-Nd Type of Bulk Nanocrystalline Alloys

2013 ◽  
Vol 203-204 ◽  
pp. 302-305
Author(s):  
Grzegorz Ziółkowski ◽  
Artur Chrobak ◽  
Joanna Klimontko
Keyword(s):  
Magnetic Properties ◽  
Coercive Field ◽  
Phase Structure ◽  
Maximum Energy ◽  
Nanocrystalline Alloys ◽  
Preparation Technique ◽  
Casting Technique ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Bulk Nanocrystalline

In this work we present phase structure and magnetic properties of the (Fe80Nb6B14)1-x Ndx (x=0.08, 0.12, 0.16) bulk nanocrystalline alloys prepared by making use of mould casting technique. The applied mould allows obtaining bulk rods of 1.5 mm in diameter and about 3 cm in length. Phase structure and magnetic properties were carefully examined. It was shown that the applied preparation technique is favorable to nanocrystallization of the alloys, which was confirmed by the XRD diffraction. For all studied alloys, one can observe a formation of mainly Nd2Fe14B (hard magnetic) and Fe phases with different contributions dependently on the x parameter. It was also shown that the alloy of (Fe80Nb6B14)0.92Nd0.08 has the best hard magnetic properties with the coercive field, magnetic saturation and maximum energy product equal to 0.2 T, 117 emu/g and 13.4 kJ/m3, respectively (at room temperature). Moreover, the coercive field and maximum energy product are gradually deteriorating with increasing of rare earth addition.

Influence of Milling Time on Magnetic Properties and Microstructure of Sintered Nd-Fe-B Based Permanent Magnets

2018 ◽  
Vol 930 ◽  
pp. 445-448
Author(s):  
R.G.T. Fim ◽  
M.R.M. Silva ◽  
S.C. Silva ◽  
Julio Cesar Serafim Casini ◽  
P.A.P. Wendhausen ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Permanent Magnets ◽  
Milling Time ◽  
Maximum Energy ◽  
Inhomogeneous Distribution ◽  
Maximum Energy Product ◽  
Grain Sizes ◽  
Energy Product

In this paper, the effect of the grain size on sintered Nd-Fe-B based permanent magnets was investigated. In order, the magnets were produced by different milling times at 200 rpm and then vacuum sintered at 1373 K for 60 minutes followed by cooling outside the furnace. The magnets either produced by lower and higher milling times (30 and 75 minutes) exhibited lower remanence and coercivity, due the inhomogeneous distribution of the grain sizes. The magnet produced by intermediary milling time (45 minutes) exhibited the highest properties among all samples, with remanence of 1.06 T, coercivity of 891.3 KA.m-1, maximum energy product of 211 KJ.m3and a squareness factor equal 0.92.

Consolidation Behavior and Magnetic Properties of Nanocrystalline Nd-Fe-B Magnets Prepared by Spark Plasma Sintering

2017 ◽  
Vol 899 ◽  
pp. 559-562
Author(s):  
Frederico Orlandini Keller ◽  
Juliano Assis Baron Engerroff ◽  
Leonardo Ulian Lopes ◽  
Nério Vicente Jr. ◽  
Paulo Antônio Pereira Wendhausen
Keyword(s):  
Magnetic Properties ◽  
Spark Plasma Sintering ◽  
Constant Pressure ◽  
Maximum Energy ◽  
Processing Temperature ◽  
Sintering Process ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Plasma Sintering ◽  
Spark Plasma

Spark Plasma Sintering (SPS) was studied as a means to consolidate Nd-Fe-B powders, previously subjected to grain refinement by HDDR (Hidrogenation–Disproportionation–Dessorption–Recombination). The sintering process was carried out under 60 MPa constant pressure, varying the maximum processing temperature from 500 °C to 900 °C with a holding time of 5 min. Densification was observed above 600 °C related to the melting of Nd-rich phase. The magnetic properties are clearly related to microstructure coarsening associated with the SPS temperature regime. A monotonic decrease for coercivity (Hcj) was observed as a function of maximum SPS operating temperature with values varying from maximum of 750 kA/m at 500 °C to less than 200 kA/m for SPS at 900 °C. Remanence (Br) and maximum energy product (BH)max showed optimum values for intermediate temperatures, since these properties benefit from the densification developed by SPS.

Recycling of Nd-Fe-B Magnets from Scrap Hard Disc Drives

2016 ◽  
Vol 682 ◽  
pp. 308-313 ◽  
Author(s):  
Mateusz Szymański ◽  
Bartosz Michalski ◽  
Marcin Leonowicz ◽  
Zbigniew Miazga
Keyword(s):  
Magnetic Properties ◽  
Chemical Composition ◽  
Nickel Coating ◽  
Maximum Energy ◽  
Chemical Methods ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Neodymium Iron Boron

A hydrogen-based treatment, including Hydrogen Decrepitation (HD) and Hydrogen Disproportionation-Desorption-Recombination (HDDR), was used as part of a recycling procedure for scrap neodymium-iron-boron magnets. Chemical methods of removing nickel coating out of magnets were tested, however ineffectively. Powders were obtained from magnets after the HD and were further processed by the HDDR. Finally, material with maximum energy product (BH)max of 74 kJ/m3 was produced. Chemical composition of magnets (MS, EDS), magnetic properties (VSM) and microstructure observations (SEM) were carried out.

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