BONDED PERMANENT-MAGNETS - CURRENT STATUS AND FUTURE OPPORTUNITIES

Permanent magnets play a vital role in modern society as a component i n a wide range of devices utilized by many industries and consumers. I n 1995, the world production of permanent magnets was estimated to be valued at $3.6 billion and growing at an annual rate of 12%. Bonded pe rmanent magnets are the fastest growing segment of this market. Bonded magnet technology enables a wide variety of magnetic powders to be co mbined with several polymer and binder systems to produce magnetic com ponents utilizing, several processing options. In this article, we rev iew the development of bonded magnet technology. The major classes of magnetic powders, binder systems, and processing technologies are desc ribed. Recent developments in magnetic material grades, e.g., anisotro pic NdFeB, rare earth lean NdFeB, SmFe(N, C) are outlined. The current status of processing and binder options aimed at increasing the upper application temperature limit of these materials is highlighted. Fina lly, the improvements and future opportunities for bonded magnets are discussed. (C) 1997 American Institute of Physics.