Improving the properties of permanent magnets : a study of patents, patent applications, and other literature
Author(s)
Bibliographic Information
Improving the properties of permanent magnets : a study of patents, patent applications, and other literature
Elsevier Science, c1991
Available at 3 libraries
Note
Includes bibliographical references
Description and Table of Contents
Description
The present study complements the study on patents, patent applications and other literature on rare earth metals based permanent magnets by Frits Andriessen and Marten Terpstra, published by Elsevier Applied Science in 1989, and complements in part the book on Nd-Fe permanent magnets edited by LV. Mitchell, which was the result of a workshop organized by the Commission of the European Communities and held in Brussels on 25 October 1984. The difference between the content of the first book and that of the present study is that the first is more specifically directed to various kinds and compositions of alloys used in newly developed magnets, while the present book emphasises the improvements obtained when using particular alloys. The study edited by Mitchell deals more specifically with the economic, physical and chemical aspects of rare earth metals based magnet alloys, their properties compared with the more common and classical magnets such as ferro-cobalt alloy magnets, and their applications to various fields of technology. From the present study it has become apparent that there exist only a few patents and patent applications covering a specific use of particular magnets having specific properties to a circuit, arrangement, device or electric motor. This appears to be due to the fact that every manufacturer of such circuits or arrangements applying magnets naturally wants to employ the most effective magnets.
Table of Contents
1. Methods to Enhance the Magnetic Properties of Magnets and Magnetic Materials.- 1.1 Improvement of magnetic characteristics in general.- 1.1.1 By specifically providing magnetic anisotropy.- 1.1.2 By using specific compositions.- 1.1.3 By providing a low average crystal grain size.- 1.1.4 By heat treatment or by hot-working.- 1.1.5 By other measures.- 1.2 Improvement of coercivity, remanent flux density and energy product.- 1.2.1 By hot working and/or heat treating.- 1.2.2 By addition of specific elements.- 1.2.3 By other measures.- 1.3 Improvement of coercivity and energy product.- 1.4 Improvement of coercivity, saturation magnetization and squareness of hysteresis loop.- 1.5 Improvement of coercivity.- 1.5.1 By addition of specific elements.- 1.5.2 By other measures.- 1.6 Improvement of remanent flux density and energy product.- 1.7 Improvement of remanent flux density.- 1.8 Improvement of energy product and square ratio.- 1.9 Improvement of magnetostrictive response.- 2. Methods to Improve the Physical and Chemical Characteristics of Magnets and Magnetic Materials.- 2.1 Improvement of corrosion resistance and thermal stability.- 2.2 Improvement of corrosion resistance.- 2.2.1 By using specific compositions.- 2.2.2 By applying a specific coating.- 2.2.3 By other measures.- 2.3 Improvement of temperature characteristics.- 2.3.1 By using specific compositions.- 2.3.2 By addition of specific elements or compounds.- 2.3.3 By other measures.- 3. Methods to Improve Other Properties and Characteristics of Magnets and Magnetic Materials.- 3.1 Improvement of workability.- 3.2 Improvement of sintering characteristics.- 3.3 Improvement of dimensions.- 3.4 Improvement of mechanical properties.- 4. Methods to Lower the Production Costs of Magnets and Magnetic Materials.- 4.1 By using commercial manufacturing processes.- 4.2 By eliminating specific costly production steps.- 4.3 By substituting inexpensive materials for expensive materials.- 4.4 By other measures.- 5. Methods to Prevent Risks During the Production of Magnets and Magnetic Materials.- 5.1 To prevent the formation of poisonous volatile boron compounds.- 5.2 To prevent the risk of explosion.- References.- Abbreviations Used.- List of Patentees.
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