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 PDF Author: G. C. Hadjipanayis
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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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).

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 PDF Author: G. C. Hadjipanayis
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Book Description
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).

Investigation of Rapidly Quenched Rare Earth Iron Alloys for Permanent Magnets

Investigation of Rapidly Quenched Rare Earth Iron Alloys for Permanent Magnets PDF Author: G. C. Hadjipanayis
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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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.

An Investigation of Anisotropic Magnetic Properties of Rare Earth Iron Boron Alloys

An Investigation of Anisotropic Magnetic Properties of Rare Earth Iron Boron Alloys PDF Author: M. J. Hawton
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Research in Progress

Research in Progress PDF Author:
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 604

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Rare Earth Permanent-Magnet Alloys’ High Temperature Phase Transformation

Rare Earth Permanent-Magnet Alloys’ High Temperature Phase Transformation PDF Author: Shuming Pan
Publisher: Springer
ISBN: 3642363881
Category : Science
Languages : en
Pages : 290

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Book Description
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.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 702

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Microstructural Investigation of Mixed Rare Earth Iron Boron Processed Via Melt-spinning and High-pressure Gas-atomization for Isotropic Bonded Permanent Magnets

Microstructural Investigation of Mixed Rare Earth Iron Boron Processed Via Melt-spinning and High-pressure Gas-atomization for Isotropic Bonded Permanent Magnets PDF Author: Nicholas Lee Buelow
Publisher:
ISBN:
Category :
Languages : en
Pages : 218

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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 PDF Author: G. C. Hadjipanayis
Publisher:
ISBN:
Category :
Languages : en
Pages : 102

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Book Description
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.

Microstructual Investigation of Mixed Rar Earth Iron Boron Processed Vis Melt-spinning and High-pressure Gas-atomization for Isotrophic Bonded Permanent Magnets

Microstructual Investigation of Mixed Rar Earth Iron Boron Processed Vis Melt-spinning and High-pressure Gas-atomization for Isotrophic Bonded Permanent Magnets PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 115

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A solid solution of three rare earths (RE) in the RE2Fe14B structure have been combined to create the novel mixed rare earth iron boron (MRE2Fe14B) alloy family. MRE2Fe14B exhibits reduced temperature dependent magnetic properties; remanence and coercivity. The desired form of MRE2Fe14B is a powder that can be blended with a polymer binder and compression or injection molded to form an isotropic polymer bonded permanent magnet (PBM). Commercially, Nd2Fe14B is the alloy of choice for PBMs. Powders of Nd2Fe14B are made via melt-spinning as can be MRE2Fe14B which allows for direct comparisons. MRE2Fe14B made using melt-spinning at high wheel speeds is overquenched and must be annealed to an optimal hard magnetic state. Due to the rare earth content in the MRE2Fe14B powders, they must be protected from the environment in which they operate. This protection is accomplished by using a modified fluidized bed process to grow a protective fluoride coating nominally 15nm thick, to reduce air oxidation. MRE2Fe14B has demonstrated reduced temperature dependent magnetic properties in ribbon and PBM form. The real challenge has been modifying alloy designs that were successfully melt-spun to be compatible with high-pressure gas-atomization (HPGA). The cooling rates in HPGA are lower than melt-spinning, as the powders are quenched via convective cooling, compared to melt-spinning, which quenches initially by conductive cooling. Early alloy designs, in gas atomized and melt-spun form, did not have similar phase compositions or microstructures. Alloy additions, such as the addition of zirconium as a nucleation catalyst, were successful in creating similar phases and microstructures in the HPGA powders and melt-spun ribbon of the same MRE2Fe14B composition.

Source Book on Neodymium-iron-boron Permanent Magnets

Source Book on Neodymium-iron-boron Permanent Magnets PDF Author: J. Capellen
Publisher:
ISBN:
Category : Magnetic alloys
Languages : en
Pages : 112

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