Rare Earth Permanent Magnets

Rare Earth Permanent Magnets presents the discussion of the metallurgy and properties of rare earth permanent magnet alloys.

The monograph initially provides the elementary aspects of magnetism to enable the reader sufficient understanding of permanent magnetism. The book then discusses the rare earth elements and their alloys with cobalt, copper, and iron; the magnetic properties of various intermetallic compounds relevant to permanent magnets; a detailed account of cast permanent magnets of the Co-Cu-Sm and Co-Cu-Ce systems and their modifications; the important methods of making and manufacturing rare earth permanent magnets by powder metallurgy methods; and comparisons between the well-known permanent magnets and the new rare earth materials.

This text will be of value to students, materials engineers, and scientists.

Preface

Acknowledgments

Chapter I. Some Elementary Aspects of Magnetism

Atomic Magnetism and Magnetic Alignment

Magnetic Domains

Magnetization

Thermal Variation of Magnetization

Magnetic Anisotropics

Permanent Magnet Materials

Appendix 1.1 Magnetic Units

Appendix 1.2 Instructions for Making a Colloidal Suspension of Magnetite and Preparing Metal Surfaces for Microscopic Observation of Domains

Appendix 1.3 Equations Used for Design of Permanent Magnets

References

Chapter II. The Rare Earth Elements and Their Alloys with Cobalt, Copper, and Iron

Electronic Nature of Rare Earth Elements

Rare Earth Alloys

Co5R and Cu5R Phases

Fe5R Phases

Multicomponent A5B Phases

Phases of Stoichiometry A17R2

Preparation of Alloys

References

Chapter III. Magnetic Properties of Intermetallic Compounds Relevant to Permanent Magnets

The Co5R Phases

Magnetocrystalline Anisotropy

The Co17R2 and Fe17R2 Phases

References

Chapter IV. Cast Permanent Magnets of the Co-Cu-Sm and Co-Cu-Ce Systems and Their Modifications

Magnetic Properties of Alloys in the Co5Sm-Cu5Sm System

Further Effect of Heat Treatment of Co5Sm-Cu5Sm Alloys

Magnetic Properties of Alloys in the Co5Ce-Cu5Ce System

Heat Treatment of the Alloy Co3.5Fe0.5CuCe

Summary of Magnetic Properties of C04.5-XCuxFe0.5Ce

External Field Supplied by Arc Melted Buttons

Magnetic Properties of Cast Alloys in the Co-Cu-Fe-Ce-Sm System, Including Alloys Containing Misch Metal (MM) in Place of Ce

Optical Metallography

Electron Diffraction and Metallography

Mechanism of Magnetization

Thermal Properties

Appendix 4.1

References

Chapter V. Co5R Permanent Magnets Based on Powders

Magnetic Behavior of Powders

Methods of Producing and Properties of Magnets

Recapitulation

References

Chapter VI. Comparison of Permanent Magnet Materials

Martensitic Magnet Steels

Alnico Magnets

Cunife and Cunico

Remalloy

Vicalloys

Platinum-Cobalt

yFe2O3 and Fe3O4

Hexagonal Ferrite (Ceramic) Magnets

Rare Earth Magnets

References

Author Index

Subject Index