Review of Permanent Magnet Applications and the Potential for High Energy Magnets

Abstract

With the development of new families of rare-earth permanent magnets, typified by sintered and bonded forms of 1:5 and 2:17 SmCo and NdFeB, the last two decades has seen a dramatic improvement in the properties of hard magnetic materials, and equally revolutionary progress in the devices and machines for which they provide the excitation. In the last 4–5 years, of course, research has been heavily concentrated on NdFeB magnets and their derivatives, which reflects the perception that they will achieve great importance and commercial value, projections to the year 2000 suggesting that ultimately they will capture 40% of the total magnet market, which is predicted to experience a three-fold increase from $1.65 billion to $5 billion. Within this scenario ferrites, because of their low cost, will continue to enjoy widespread use, retaining some 50% of the market, with other magnet materials accounting for just 10%.