一、引言永磁体的重要特性是因它对铁磁体材料不论在吸引或排斥时它们无需接触,并在不输进能量的情况下提供永久的磁通量,所以没有运行费用。这就开辟了多种多样的以永磁体来代替电磁铁装置的可能性。随着永磁材料的改进,这种取代的机会也增多了。过去20来年,强力永磁材料的开发取得了重要的进展。这些 I. INTRODUCTION The important characteristic of permanent magnets is that they have no operating costs because they do not require contact with the ferromagnetic material either when attracted or rejected and provide a permanent magnetic flux without input of energy. This opens up the possibility of using permanent magnets instead of electromagnet devices. As permanent magnet materials improve, the chances of such substitutions have increased. Over the past 20 years, strong permanent magnet material development has made important progress. These ones