Investigation of Rapidly Quenched Rare Earth Iron Alloys for Permanent Magnets
Investigation of Rapidly Quenched Rare Earth Iron Alloys for Permanent Magnets

Author: G. C. Hadjipanayis

Publisher:

Published: 1985

Total Pages: 5

ISBN-13:

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In early in 1985 the potential of FeNd (Pr) B (SI) alloys for permanent magnet development was demonstrated. The progress under consideration was initiated in April 1983, to study the properties of these materials in more details and in particular to understand the origin of magnetic hardening by correlating the magnetic properties with the microstructure determined by transmission electron microscopy. The magnetic properties of melt-spun Fe-R-B alloys have been examined in the whole rare-earth series. The tetragonal Fe14R2B phase occurs in all alloys studied except in Eu and Yb containing alloys. The Curie temperature of this phase increases from about 170C in Fe14CeB to 375 for Fe14Gd2B and then decreases for the heavier rare-earths and is only 320 C in Fe14Ho2B. In heavy rare-earths, a second phase with a higher Curie temperature approx.(470 C) has also been observed. The nature of this phase is not yet known. The magnetic hysteresis properties of melt-spun Fe-light rare-earth-boron alloys were examined and maximum coercivities were found to scale with the anisotropy fields.

Rare-Earth Permanent Magnets
Rare-Earth Permanent Magnets

Author: I.R. Harris

Publisher: Elsevier

Published: 2014-04-03

Total Pages: 144

ISBN-13: 0080983634

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These papers provide an interesting collection of contributions on fundamental magnetic behaviour, microstructural studies, processing methods and applications of rare earth, iron-rich, high performance permanent magnets. The remarkably versatile nature of the Nd-Fe-B-type alloys with respect to magnet processing is very evident in these proceedings. Thus there are papers which describe the production of magnets by the die-upset-forging of melt-spun ribbon, by cold-compaction of melt-spun-ribbon with soft metals, by mechanical alloying and by hot working of cast material. Work is also reported on the production of new permanent magnets from melt-spun material based on the alloys Nd4Fe78B18 and SmFe11.5Ti1.04. Both these alloys look promising and the former appears to be close to commercial exploitation.

Rare Earth Permanent-Magnet Alloys’ High Temperature Phase Transformation
Rare Earth Permanent-Magnet Alloys’ High Temperature Phase Transformation

Author: Shuming Pan

Publisher: Springer

Published: 2014-12-01

Total Pages: 290

ISBN-13: 3642363881

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The process of high temperature phase transition of rare earth permanent-magnet alloys is revealed by photographs taken by high voltage TEM. The relationship between the formation of nanocrystal and magnetic properties is discussed in detail, which effects alloys composition and preparation process. The experiment results verified some presumptions, and were valuable for subsequent scientific research and creating new permanent-magnet alloys. The publication is intended for researchers, engineers and managers in the field of material science, metallurgy, and physics. Prof. Shuming Pan is senior engineer of Beijing General Research Institute of Non-ferrous Metal.

Rapidly Solidified Neodymium-Iron-Boron Permanent Magnets
Rapidly Solidified Neodymium-Iron-Boron Permanent Magnets

Author: John J. Croat

Publisher: Woodhead Publishing

Published: 2017-10-24

Total Pages: 384

ISBN-13: 0081022263

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Rapidly Solidified Neodymium-Iron-Boron Permanent Magnets details the basic properties of melt spun NdFeB materials and the entire manufacturing process for rapidly solidified NdFeB permanent magnets. It covers the manufacturing process from the commercial production of the melt spun or rapidly solidified powder, to the production and properties of both isotropic bonded Nd and hot deformed anisotropic NdFeB magnets. In addition, the book discusses the development and history of bonded rare earth transition metal magnets and the discovery of the NdFeB compound, also covering melt spun NdFeB alloys and detailing the magnetization process and spring exchange theory. The book goes over the production of melt spinning development, the operation of a melt spinner, the processing of melt spun powder, commercial grades of NdFeB magnetic powder and gas atomized NdFeB magnetic powders. Lastly, the book touches on the major application and design advantages of bonded Nd Magnets. Features a unique perspective as the author is not only the inventor of NdFeB magnetic powder, but also played a key role in developing many of the technologies covered Provides a comprehensive look at the history, fundamental properties, production processes, design and applications of bonded NdFeB magnets Includes discussion of the rare earth supply challenge, politics, and systems as it impacts bonded NdFeB magnets

Investigation of Crystalline Iron-Platinum Nickel and Amorphous Rare Earth-Iron Alloys for Permanent Magnets
Investigation of Crystalline Iron-Platinum Nickel and Amorphous Rare Earth-Iron Alloys for Permanent Magnets

Author: G. C. Hadjipanayis

Publisher:

Published: 1983

Total Pages: 102

ISBN-13:

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Samarium-cobalt magnets have large-energy products but their cost is relatively high because of the use of expensive Sm and Co. A recent trend has been observed in industry to encourage conservation of cobalt and to find possible substitutes for this strategic material. The purpose of this program was to develop a permanent magnet without the use of cobalt which could be substituted for the AlNiCo commercial magnets. A number of magnetic materials were identified with properties that could be exploited in permanent magnet development. Contents: Experimental Techniques; Praseodymium-Iron-Gallium Alloys; Ternary Rare-Earth System; Praseodymium(Misch-Metal)-Terbium-Iron-Cobalt-Glass Former; Praseodymium-Iron(cobalt)-Glass Former; Iron-Platinum Based Alloys; Appendix: 'Characterization Studies of Rare Earth-Iron Magnetic Materials.

Investigation of As-Cast Iron-Light Rare-Earth-Boron Alloys for Permanent Magnets
Investigation of As-Cast Iron-Light Rare-Earth-Boron Alloys for Permanent Magnets

Author: G. C. Hadjipanayis

Publisher:

Published: 1988

Total Pages: 16

ISBN-13:

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The magnetic and structural properties of Fe-R-B magnets were studied in the melt-spun and sintered state. The formation of Fe14R2B phase including its magnetic properties (Curie temperature, magnetic moment and coercivity) and the effects of partial substitutions of iron, rare-earth and metalloid were studied in melt-spun samples. The magnetic properties of as-cast Fe-R-B powders were examined as a function of particle size. The fine powders were sintered into dense magnets and the properties of the magnets were examined over a range of temperatures. The magnetic properties of all samples (melt-spun, powders and sintered magnets) were correlated with the microstructure and magnetic domain structure in an attempt to elucidate the origin of magnetic hardening in these materials. The results of these studies indicate that the high coercivities are due to domain wall pinning at grain boundaries in ribbons and sintered magnets and at the surface of the particles in powders. Keywords: Permanent magnet materials; Iron; Rubidium; Boron; Magnetic hardening; Rare earth alloys. (jes).

Hard Magnetic Alloys
Hard Magnetic Alloys

Author:

Publisher: Springer

Published: 1992-12-16

Total Pages: 0

ISBN-13: 9783540554639

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Volume 19 of Group III (Crystal and Solid State Physics) deals with the magnetic properties of metals, alloys and metallic compounds. The amount of information available in this field is so substantial that several subvolumes are needed to cover it all. Subvolumes III/19a through III/19f treat the intrinsic magnetic properties, i.e. those magnetic properties which depend only on the chemical composition and the crystal structure. So far, subvolumes III/19a, III/19b, III/19c, III/19d1, III/19d2, III/19e1, III/19e2 and III/19f1 have appeared. Data on the properties that depend on the preparation of the samples measured, as for instance, thin films, amorphous alloys or the magnetic alloys used in technical applications, are being compiled in the subvolume of III/19g (Thin Films) and III/19h which covers the magnetic properties of liquid quenched alloys containing transition elements. This subvolume III/19i2 deals with the magnetic properties of hard magnetic alloys for permanent magnets. The large fields of both the well-known magnets based on 3d elements and the currently widely investigated alloys based on rare earth elements are covered. The relation between the permanent magnet properties and the various preparation techniques of the alloys has obtained special attention.