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.

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.

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.

Bulk metallic glass formation, composite, and magnetic propertiesof Fe-B-Nd based alloys

2009 ◽  
Vol 24 (2) ◽  
pp. 357-371 ◽  
Author(s):  
J. Zhang ◽  
Y.P. Feng ◽  
Y. Li
Keyword(s):  
Glass Formation ◽  
Magnetic Phase ◽  
Industrial Applications ◽  
Maximum Energy ◽  
Quaternary Alloys ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Hard Magnets ◽  
Hard Magnet ◽  
Hard Magnetic Properties

The glass formation in Fe-rich ternary Fe-B-Nd and quaternary (Fe,B,Nd)96Nb4 alloys has been studied and the best ternary and quaternary glass formers are located at Fe67B23Nd10 and (Fe68B25Nd7)Nb4 with critical diameters of 1 and 4 mm, respectively. For (Fe,B,Nd)96Nb4 alloys, the competing phases with glass were identified by monitoring the microstructure change. Fe14Nd2B was discovered to be one competing phase, which is the principle magnetic phase for Nd-Fe-B hard magnets. Composites with uniformly distributed Fe14Nd2B were formed for quaternary alloys with a diameter of 1.5 to 3 mm. Bulk hard magnets could be obtained by directly annealing the composites in a compositional area. A hard magnet with a coercivity of 1,100 kAm−1 and a maximum energy product, (BH)max, of 33 kJm–3 was obtained at (Fe67B23Nd10)96Nb4 by annealing. The combination of hard magnetic properties and the large critical sample size may make these alloys a commercially viable candidate for industrial applications.

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.

scholarly journals Nanocomposite permanent magnetic materials Nd-Fe-B type: The influence of nanocomposite on magnetic properties

2005 ◽  
Vol 41 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Nadezda Talijan ◽  
Jasna Stajic-Trosic ◽  
Aleksandar Grujic ◽  
Vladan Cosovic ◽  
Vladimir Menushenkov ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Permanent Magnet ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
New Type ◽  
Permanent Magnet Materials

The influence on the magnetic properties of nanocristalline ribbons and powders has character of microstructure, between others ? the grain size volume of hard and soft magnetic phases and their distribution. Magnetic properties of ribbons and powders depend mainly on their chemical composition and parameters of their heat treatment [1]. Technology of magnets from nanocristalline ribbon consists of the following process: preparing the Nd-Fe- B alloy, preparing the ribbon, powdering of the ribbon, heat treatment of the powder and finally preparing the magnets. Nanocomposite permanent magnet materials based on Nd-Fe- B alloy with Nd low content are a new type of permanent magnetic material. The microstructure of this nanocomposite permanent magnet is composed of a mixture of magnetically soft and hard phases which provide so called exchange coupling effect.

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.

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