Rare-Earth Magnets and
Their Applications

Edited by

H. Kaneko
M. Homma
M. Okada

Copyright © 2000, The Japan Institute of Metals
All right reserved
Published by The Japan Institute of Metals
Aramaki Aoba, Aoba-ku, Sendai 980-0845, Japan
Tel: +81-22-223-3685, Fax: +81-22-223-6312

Vol. 1

Preface H. Kaneko, M. Homma and M. Okada

Karl Strnat Memorial Lecture

Y. Tawara ······· 1

A Tribute to Marlin S. Walmer

F. G. Jones, C. H. Chen, M. H. Walmer, A. E. Ray and M. G. Benz ······· 5

Session 1: Rare Earth Magnets & Markets

Development of Rare Earth Iron Permanent Magnets

M. Sagawa ······· 17

The Role of China's Rare Earth in the Globe

J. Yan and J. Xiong ······· 25

Further Development of Rare Earth Magnet Industry in China

Y. Luo ······· 31

Session 2: Sintered Magnets I

Magnetic Hardening, Thermal Stability, and Microstructures for a New Class of Sm-TM High Temperature Magnets

M. S. Walmer, C. H. Chen, M. H. Walmer, S. Liu and E. Kuhl ······· 41

Micromagnetic and Microstructural Analysis of the Temperature Dependence of the Coercive Field of Sm2(Co, Cu, Fe, Zr)17 Permanent Magnets

D. Goll, W. Sigle, G. C. Hadjipanayis and H. Kronm üller ······· 61

Sintered Permanent Magnet Materials Based on SmCo7 Phase

S. Liu, E. Kuhl, C. H. Chen, M. H. Walmer, W. Gong and P. Liu ······· 71

Session 3: Sintered Magnets II

Rare-Earth Magnets with High Energy Products

Y. Kaneko ······· 83

High-Energy-Product (Pr-Nd-Ce)FeB Magnets Produced Directly from Mixed-Rare-Earth-Oxide Feed for MRI Medical Imaging Applications

M. G. Benz, J. C. Shei, C. H. Chen, M. S. Walmer and F. M. Doyle ······· 99

High Performance Sintered Nd-Fe-B Magnets Made by New RIP from SC Alloys

S. Sasaki, J. Fidler and M. Sagawa ······· 109

Production of Sintered Nd-Fe-B Magnets with a Maximum Energy Density of 53 MGOe

W. Rodewald, R. Blank, B. Wall, G. W. Reppel and H. D. Zilg ······· 119

Corrosion Behavior of Nd-Fe-B Sintered Magnets in the Refrigerant/Lubricant System

R. Hamada, K. Tamura, M. Shimao and T. Minowa ······· 127

Session 4: Materials & Processing

Study of the Process of Didymium-Iron Double Alloy Calcium-Thermal Obtaining (Dd-Fe)

Y. Putilov, M. Kotsar, A. Mukchachev, M. Morozova and Y. Shestak ·······139

Implementation of a New Rare-Earth Industry in Brazil

F. Beneduce, D. Rodrigues, P. F. Nogueira, F. J. G. Landgraf and S. Marques ······· 149

High Temperature Sm2(Co, Fe, Cu, Zr)17 Magnets and their Dynamic Thermal Stability

S. Liu, E. Kuhl, C. H. Chen, M. S. Walmer, M. H. Walmer and W. Gong ······· 159

Evolution of Microstructure and Microchemistry in the High Temperature Sm(Co, Fe, Cu, Zr)Z Magnets

Y. Zhang, W. Tang, G. C. Hadjipanayis, D. Goll,H. Kronmüller, C. H. Chen, C. Nelson and K. Krishnan ······· 169

Effect of Composition and Heat Treatment on the Microstructure and Magnetic Properties of Sm(CobalFevCuyZrx)z Magnets

W. Tang, Y. Zhang, J. F. Liu, C. H. Chen and G. C. Hadjipanayis ······· 179

Effect of CoFeCuZr Coat on Anisotropic Thermal-Expansion of the Sm2Co17 Magnets

W. Pan, W. Li, L. Y. Cui, Z. H. Guo and S. Z. Dong ·······189

Structure and Magnetic Properties of SmCo7−xMnx Alloys

M. Gjoka, O. Kalogirou, D. Niarchos and G. C. Hadjipanayis ·······195

Microstructures and Magnetic Properties of Strip Cast Sm2Co17 Sintered Magnets

K. Sakaki, K. Sato, T. Hashimoto, H. Nakamura and T. Minowa ·······205

Improvement of Manufacturing of High-Energy Permanent Magnets Didymium-Iron-Boron

Y. Putilov, M. Morozova, Y. Shestak, S. Ustinova and N. Yanchik ·······215

Hydrogen Vibration Milling (HVM): An Effective Route of Powder Preparation for Production of RE-Fe-B Sintered Magnets

A. Kianvash and I. R. Harris ·······223

Binary Powder Blending Technique (BPBT): An Effective Method in Production of (Nd, MM)2(Fe, Co, Ni)14B-Type Corrosion Resistant Magnets

H. R. Madaah-Hosseini, A. Kianvash, M. Seyyed-Reihaniand H. Yoozbashi-Zadeh ······· 229

Temperature Dependence of Magnetic Domain Structure in Nd-Fe-B Sintered Magnets

C. Ishizaka, H. Nishio, E. Kato and A. Fukuno ······· 237

Effect of Blending Additions on the Sintering Behaviour of NdFeB-Type Magnets

R. S. Mottram, B. E. Davies, M. G. Taylor and I. R. Harris ······· 247

Effect of Metal-Coating and Consecutive Heat Treatment on Coercivity of Thin Nd-Fe-B Sintered Magnets

K. T. Park, K. Hiraga and M. Sagawa ······· 257

The Flexural Characteristics of Nd-Fe-B Sintered Magnets

K. Mitake, N. Kataoka, S. Hashimoto and K. Yajima ······· 265

A Study of Grain Growth Kinetics in Sintered NdFeB Magnets

L. Xianglian, Z. Shouzeng and D. Qingfei ······· 275

Thermomagnetic Characteristics of Rare-Earth-Transition Metals Raw Materials Produced by Reduction-Diffusion Processes

D. Rodrigues, M. Emura, S. R. Janasi, F. J. G. Landgraf and F. Beneduce Neto ······· 283

Relationships in the Fe-Nd/Sm/Pr-B Phase Diagrams Determined by Iron Crucible Reaction Analysis (ICRA)

A. Luedtke, B. Stahl, I. R. Harrisand G. S. Schneider ······· 291

The Role of Lattice Defects on the Coercivity of Nucleation Controlled (NdFeB, SmCo5) Magnets

M. F. de Campos and F. J. G. Landgraf ······· 297

Effects of Zn Coating on the Microstructure and Magnetic Properties of Nd-Fe-B Magnets

Y. Hu, M. Aindow, I. P. Jones and I. R. Harris ······· 307

Effects of Zinc Interdiffusion on the Magnetic Properties and Corrosion Resistance of NdFeB Powder Particles

A. Walton, J. D. Speight, A. J. Williams and I. R. Harris ······· 315

Corrosion Protection of NdFeB-Based Rare-Earth Permanent Magnets

P. B. Gwan, S. J. Collocott and J. B. Dunlop ······· 325

Microstructure and Magnetic Properties of Hot Worked Nd-Fe-B Magnets

A. Bovda, V. Finkel, D. Kutniy, L. Onishenko, O. Utva and V. Bovda ······· 331

NdFeB Magnets Prepared by a High-Speed Forging Process: Microstructure and Magnetic Properties

S. Rivoirard, P. de Rango, D. Fruchart,R. Perrier de la Bâthie and D. Chateigner ······· 337

Anisotropic and Coercive NdFeB Powder for Bonded Magnets

S. Rivoirard, J. G. Noudem, P. de Rango, D. Fruchart, S. Liesertand J. L. Soubeyroux ······· 347

Production of Anisotropic Powder from Hot Deformed RE-Fe-B-Cu Alloys

V. S. J. Burns, A. J. Williams and I. R. Harris ······· 355

Ultrasonic Characterization of Deformation Related Parameters of Nano-Crystalline Nd-Fe-B Magnets

S. Prakash Narayan, J. Prasad and D. K. Hsu ······· 365

Solidification Behavior of Undercooled Nd-Fe-B-Ti-C Melts in Dependence on Cooling Parameters and Composition

R. Hermann, O. Filip, N. Mattern and L. Schultz ······· 375

The Magnetic and Microstructural Properties of DC Magnetron Sputtered Nd-Fe-B Films Processed by Post-Deposition Vacuum Annealing

M. A. Parry, I. R. Harris and P. J. Grundy ······· 385

Nd-Fe-B Thin Films of High Coercivity Prepared by Post-Annealing

K. Terazawa, L. Serrona, T. Okuda, N. Adachi, I. Sakamoto and A. Nakanishi ······· 393

Effect of Cr Underlayer on Microstructure and Magnetic Properties of Sm2Co17 Thin Films

S. K. Chen, G. Y. Wu and T. S. Chin ······· 403

Effects of Nd Layer on the Magnetic Properties and Microstructure of Sputtered Nd-Fe-B Thin Films

T. Shima, E. Aoyagi and H. Fujimori ······· 411

Magnetic Properties, Microstructure and Stability of NdFeB Magnets with Low Nd Content

St. Alexandru, W. Kappel, N. Stancu, M. Codescu,I. Ivan and M. Mihaescu ······· 419

Session 5: Nanophase Magnets I

Current Status in Bonded Nd-Fe-B Magnets

V. Panchanathan ······· 431

Review of Rare Earth Nanocomposite Magnets

Z. Chen, Y. Zhang, M. Daniil, H. Okumura,G. C. Hadjipanayis and Q. Chen ······· 449

Hard Magnetic Properties of Melt-Spun (Nd, Dy)2Fe14(C, B) Ribbons with High Coercivity

J. B. Yang, A. Handstein, O. Gutfleisch, A. Kirchner,D. Eckert and K.-H. Müller ······· 465

Effect of Pre-Alloying Condition on the Bulk Amorphous Alloy Nd60Fe30Al10

A. S. O'Connor, L. H. Lewis, R. W. McCallum, K. W. Dennis,M. J. Kramer, D. T. Kim Anh, N. H. Dan, N. H. Luong and N. X. Phuc ······· 475

Session 6: Nanophase Magnets II

Nanophase Pr and Nd/Pr-Based Rare Earth-Iron-Boron Alloys

H. A. Davies, J. I. Betancourt R. and C. L. Harland ······· 485

Effects of Simultaneous Cu-and-Nb-Doping on Phase Constitution and Magnetic Properties in Nd-Fe-B-Cr-Co-Based Fe3B/Nd2Fe14B-Type Nanocomposite Permanent Magnets

T. Miyoshi, H. Kanekiyo and S. Hirosawa ······· 495

Microstructure and Hard Magnetic Properties of Cu and Nb Containing Nd-Fe-B Nanocomposites

D. H. Ping, Y. Q. Wu, H. Kanekiyo, S. Hirosawa and K. Hono ······· 505

Microstructure of Alpha-Fe/NdFeB Type Nanocomposite Magnets

M. Yamasaki, H. Mizuguchi, M. Hamano, T. Kobayashi, K. Hono,H. Yamamoto and A. Inoue ······· 513

Session 7: Thin Films & Forged Magnets

High Performance Hard Magnetic Nanocomposite Films

J. P. Liu, Y. Liu, R. Skomski and D. J. Sellmyer ······· 523

Preparation and Properties of [NdFeB/Nb]n Multi-Layer Films

J. L. Tsai, T. S. Chin and H. Kronmüller ······· 537

Fabrication and Magnetic Properties of Nanophase Dispersed Nd2Fe14B/α-Fe and SmFe12/α-Fe Films with Crystallite Orientation of Hard Phases

H. Kato, M. Ishizone, T. Miyazaki, K. Koyama, H. Nojiri and M. Motokawa ······· 547

Magnetic Properties of SmCo Nano Films Grown by a Nd-YAG Pulsed Laser Ablation Method

C. J. Yang and S. W. Kim ······· 557

High Speed NdFeB Forged Magnets: Rheological Study of Hot Deformation and Related Permanent Magnets Properties

S. Rivoirard, P. de Rango, D. Fruchart, Y. Chastel and C. L. Martin ······· 565

The Structure-Property Correlation of Hot Deformed Melt-Spun Nd-Fe-B Magnet.

S. Prakash Narayan ······· 575

Vol. 2

Session 8: Bonded Magnets

Effect of Pr Substitution on the Magnetic Properties of Nd-Fe-Co-Cu-Nb-B System Exchange Spring Magnets

H. Yamamoto, S. Koumo and K. Kawamata ······· 585

The Effect of Co and Zr Substitutions on the Magnetic Properties of Nanostructured Didymium (Nd-Pr)-Fe-B Alloys

J. I. Betancourt R. and H. A. Davies ······· 595

Magnetic Properties and TEM Studies of Boron Enriched (Nd0.95La0.05)9.5-11.5Febal. Ti2B10.5 and (Nd0.95La0.05)11Febal.Ti2Co0-15B10.5 Ribbons

W. C. Chang, S. H. Wang, S. J. Chang and H. W. Chang ······· 605

Magnetic Properties and Microstructure Studies of α-Fe/R2Fe14B-Type Nanocomposite Ribbons with Low Boron and High Boron Concentration

W. C. Chang, I. A Chen, S. J. Chang and C. H. Yu ······· 613

Magnetic Hysteresis Properties and Structural Features of Nanocrystalline Nd9Fe84B7 Alloy Prepared by Melt-Spinning and Severe Plastic Deformation

A. G. Popov, A. S. Ermolenko, V. S. Gaviko, N. N. Schegoleva,V. V. Stolyarov and D. V. Gynderov ······· 621

Magnetic Properties of Nd-Fe-Co-V-B System Bulk Exchange-Spring Magnets Formed by Spark Plasma Sintering Method

H. Ono, M. Shimada, A. Fujiki, H. Yamamoto, M. Sonoda and M. Tani ······· 631

High-Performance Nanocrystalline PrFeB-Based Bonded Permanent Magnets

D. Goll, I. Kleinschroth and H. Kronmüller ······· 641

Magnetic Properties of Nanocrystalline Pr5Fe77−xCrxB18 Alloys

A. Barra-Barrera, R. K. Murakami and V. Villas-Boas ······· 651

Solidification of Nd-Fe-B Melts under Microgravity Conditions

S. Ozawa, J. Yoshizawa, T. Saito and T. Motegi ······· 661

Nanostructure Formation in Mechanically Milled Nd-Fe-B Alloys

W. Kaszuwara, M. Leonowicz, M. Psoda, C. Harland and H. A. Davies ······· 669

Comparative Study of Precipitation-Hardened and Mechanically Alloyed Pr-Zr-Co Magnets with High Coercivity

A. M. Gabay, Z. M. Chen, Y. Zhang and G. C. Hadjipanayis ······· 677

Effects of High Pressure Hot Compaction on the Formation, Microstructure and Magnetic Properties of Melt-Spun α-Fe/Re2Fe14B-type Nanocomposite Magnets

W. Zuocheng, Z. Shouzeng, Z. Maocai and Q. Yi ······· 687

Characteristics of Epoxy Resin Bonded Magnets Prepared from Recycled Nd-Fe-B Based Melt-Spun Powder.

F. Yamashita, T. Terada, H. Onishi and H. Fukunaga ······· 695

Crystallization and Magnetic Properties of Nd2Fe14B/Fe3B Based Exchange Coupled Magnetic Materials

S. Dong, X. Li, W. Li and W. Pan ······· 703

The Effect of Tungsten Addition on the Magnetic Properties and Microstructure of Nd-Fe-B Magnets

W. Kaszuwara, M. Leonowicz and J. Kozubowski ······· 711

Isotropic Sm-Zr-Fe-Co-B-N Bonded Magnets with High (BH)max

S. Sakurada, K. Nakagawa, F. Kawashima, T. Sawa, T. Arai and M. Sahashi ······· 719

Magnetic Properties and Demagnetization Process of Sm-Fe-N-Based Nanocomposite Flakes

H. Fukunaga, T. Matsuo and F. Yamashita ······· 727

Magnetic Properties of Nitrided Sm-Fe Powders Prepared by Gas-Atomization, Rotating-Disk Atomization and Melt-Spinning Processes

R. Omatsuzawa, N. Okochi, Y. Fujita, T. Nishio and T. Iriyama ······· 735

Injection Molded Anisotropic Magnet with Zinc-Treated Sm2Fe17N3 Powder

T. Ishikawa, T. Iseki, K. Yokosawa, A. Kawamoto,I. Kaneko and K. Ohmori ······· 745

Multi-Stage Recombination Process for Producing HDDR Anisotropy NdFeB Powders

X. Liu, Y. F. Xiao, M. Yue, A. Sun and R. Wang ······· 751

The Production and Characterisation of Highly Anisotropic PrFeCoB-Type HDDR Powders

N. Cannesan, D. N. Brown, A. J. Williams and I. R. Harris ······· 757

Structure Changes in Sm2Fe17-based Permanent Magnet Materials Induced by HDDR Process

Z. Liu, T. Ohsuna, K. Hiraga and M. Tobise ······· 767

TEM Study of Microstructures in Nd-Fe-B Based Alloys Produced by the Modified HDDR Process

M. Itakura, T. Ishimi, N. Kuwano, K. Oki,R. Nakayama, K. Igarashi, K. Mori and K. Morimoto ······· 777

Development 2-Step Compression Molding for Nd-Fe-B Anisotropic Bonded Magnets

H. Mitarai, Y. Sugiura, H. Matsuoka and Y. Honkura ······· 787

The Effect of HDDR on the Structure and Magnetic Properties of Sm-Fe-Ti-B-N Powders

M. Tobise, Z. Liu, M. Shindoh, S. Tanigawa and K. Hiraga ······· 793

Ta-Doped SmFe Nitrides

P. J. McGuiness, K. Zu´zek, G. Dra´zic and S. Kobe ······· 803

Enhancement of Heat Resistance of Nd-Fe-B Anisotropic Magnet by Dy Addition in HDDR Process

N. Hamada, C. Mishima, H. Mitarai and Y. Honkura ······· 813

Observation by Mössbauer Effect Spectroscopy of the Formation of t-Fe3B in Solid and Coventional Hydrogen Disproportionated Nd-Fe-B Alloy

F. D. Saccone, F. H. Sánchez, C. Rodríguez Torres,B. Gebel and O. Gutfleisch ······· 821

Sm2(Fe, Ga)17Cy Magnets

M. Kubis, K.-H. Müller, A. Kirchner, L. Schultz and I. R. Harris ······· 827

Magnetic Properties and Stability of Bonded Magnets Produced from Zn Metal-Sorbed Nd-Fe-B HDDR Powders

K. Machida, K. Noguchi, M. Nishimura, M. Hamaguchi and G. Adachi ······· 835

Preparation and Characterization of Composite-Type Bonded Magnets of Sm2Fe17Nx and Nd-Fe-B HDDR Powders

K. Noguchi, K. Machida and G. Adachi ······· 845

Preferential Site Occupancy of Zr in Nd2 Fe14B Based Magnets; Effect of Concentration and HDDR Process

M. Matsuura, A. Ashfaq, K. Konno and M. Sakurai ······· 855

Session 9: HDDR Process

Production of Anisotropic Nd-Fe-B HDDR Powder with High Coercivity

K. Igarashi, K. Mori, K. Morimoto, R. Nakayama, M. Itakura,N. Kuwano, K. Oki ······· 865

Magnetic Properties of NdFeB Anisotropic Magnet Powder Produced by the d-HDDR Method

C. Mishima, N. Hamada, H. Mitarai and Y. Honkura ······· 873

Exchange Coupled Sm2Co17 Magnets Obtained by Reactive Milling and Recombination

O. Gutfleisch, A. Bollero, D. Eckert, B. Gebel,M. Kubis, K.-H. Müller and L. Schultz ······· 883

Localisation of Zr, Nb, and Ga in Nd-Fe-B Alloys: An X-Ray Absorption Fine Structure Study

P. de Rango, F. N. Genin, D. Fruchart,A. Traverse, S. Rivoirard and I. Popa ······· 893

Session 10: Applications I

Application of Halbach Cylinders to Electrical Machines

D. Howe and Z. Q. Zhu ······· 903

The Application of RE Magnets in Electrical Machines

R. E. Hanitsch ······· 923

Session 11: Applications II

RE Bonded Magnet for High Performance Motors

F. Yamashita ······· 937

Improved Representation of the Magnetization and Resulting Field in Isotropic NdFeB

P. Campbell, D. Miller, J. Simkin and Y. Zhilichev ······· 955

Analytical Design of New Linear Actuators and Loudspeaker Motors

M. Berkouk, V. Lemarquand and G. Lemarquand ······· 963

A Novel Electromagnetic Planar Actuator with Neodymium-Iron-Boron Permanent Magnets

A. F. Flores Filho, A. A. Susin and M. A. da Silveira ······· 973

Session 12: Applications III

Preparation of TbFe2 Thin Film by Ion Plating Process

Y. Matsumura, H. Uchida, M. Ono and H. Kaneko ······· 985

Recent Progress of Giant Magnetostrictive Materials in China

S.-Z. Zhou, X. Gao, M. Zhang and Z. Shi ······· 995

Analysis of Gap Winding Motor with Rare-Earth Permanent Magnets

T. Higuchi, J. Oyama and E. Yamada ······· 1001

Backward Extruded Ring Magnets in Rotary Electric Machines

D. Hinz, P. O'Beirne, A. Kirchner, W. Stass, O. Gutfleisch,V. Panchanathan, K.-H. Müller and L. Schultz ······· 1011

Design and Analysis of a Reciprocating Moving-Magnet Actuator Employing Bonded NdFeB Magnets

R. E. Clark, G. W. Jewell and D. Howe ······· 1021

Motor Simulation on Interior Permanent Magnet Motor

K. Miyata and K. Ohashi ······· 1031

Modular Permanent Magnet Brushless Machines for Aerospace and Automotive Applications

K. Atallah and D. Howe ······· 1039

A Sensorless High-Speed Brushless DC Motor

J. D. Ede, Z. Q. Zhu and D. Howe ······· 1049

Spiral-Type Magnetic Micro-Machine

K. Ishiyama, M. Sendoh, A. Yamazaki, K. I. Arai and M. Inoue ······· 1059

Design of Metal Mold with Closed Magnetic Circuit using Plastic-Bonded Anisotropic Magnet

Y. Matsuyama, H.-Y. Zhao and D.-Y. Ju ······· 1067

Optimum Design of Magnetic Circuits Using a Rosenblock Method

K. Kakuno and K. Ohashi ······· 1075

Application of Rare Earth Magnet to Magnetic Tracking System for Automobile

Y. Honkura, H. Toki and M. Yamamoto ······· 1083

A Magnetic Water-Treatment Device: The Influence of Magnetic Field on the Crystallisation Form of Calcium Carbonate

S. Kobe, G. Drazi´c and P. J. McGuiness ······· 1093

Clinical Observation of Rare-Earth Magnetic Acne-Remedial Beauty Mask with Chinese Medicine in Treatment for Acne

C. S. Zhao and D. L. Dong ······· 1103

Development of a Thin Dental Magnetic Attachment with Capped Magnetic Circuit

L. Tian, A. Watarai, K. Arai and Y. Honkura ······· 1107

Electromagnetic Wave Absorption of α-Fe Structure Produced by Disproportionation Reaction of Sm2Fe17 Compound

T. Maeda, S. Sugimoto, T. Kagotani, D. Book, M. Homma,H. Ota and Y. Houjou 1113

Magnetic Field Adjustment on Variable Polarizing Undulator (APPLE-2)

H. Kobayashi, K. Kakuno, N. Hirota and K. Ohashi ·······1121

The Pulsed Field Magnetometer - a Tool for Characterizing Permanent Magnets

R. Grössinger, M. Küpferling, A. Wimmer, M. Taraba, W. Scholz,J. Dudding, P. Lethuillier, B. Enzberg-Mahlke,W. Fernengel and G. Reyne ······· 1129

Manufacturing Process and Property Analysis of Magnetic Material with Positive Magnetic Temperature Coefficient

Y. Matsuyama, D.-Y. Ju and H.-Y. Zhao ·······1139

Magnetic Hardening in Glass Coated Microwires

J. González, A. Zhukov and M. Vazquez ······· 1149

Permanent Magnet Sensor for Large Linear Displacement

J.-P. Yonnet, M. Tur and J.-Y. Voyant ······· 1155

Analytical Modelling of Different Structures of Permanent Magnet Motors for Electric and Hybrid Vehicles

A. Fonseca, C. Chillet, J.-P. Yonnet, P. Langry and A.-L. Bui-Van ······· 1163

Author Index

······· 1173

Subject Index

······· 1176