Present and future technological applications of permanent magnets

A high value of
(BH)_{\max}
is not the most important material characteristic for all applications of permanent magnets, and, in discussing a number of ways in which magnets are used, an attempt is made to show what are desirable properties. Among uses of permanent magnets that are particularly mentioned are the production of fields greater than 20 000 gauss; a novel magnetic bearing for a spindle rotating at 700 000 r/min; lifting and holding devices, including large ones with improved switching mechanisms; and a proposal for vehicles supported by magnetic repulsion in place of wheels. An attempt is made to apply modern methods of forecasting future trends and choosing profitable lines of research on permanent magnets. It is concluded that permanent magnet properties can reasonably be expected to continue to increase, perhaps even at an increased rate, but it may be equally important to reduce costs by improved design and methods of manufacture.