2010 Volume 57 Issue 1 Pages 19-26
Strong magnetization for Nd-Fe-B isotropic bonded magnets is an important technology that contributes to miniaturization of electromagnetic devices and smaller fractional movement. This technology, especially the fine pole-pitch magnetization, is significant in stepper motors installed in portable terminals, etc. However, as Nd-Fe-B magnets have a high coercivity, large amounts of energy are required for magnetization. Miniaturization of devices is associated with insufficient magnetization characteristics due to the limitations of current density. So, we developed a new magnetization method using a heating system. This method involves cooling in the magnetizing field by permanent magnets after rapid heating to temperatures above the Curie point of the Nd-Fe-B magnet. This method, which we called the Ultra High Magnetizing (UHM) Process, achieved greater magnetization characteristics than conventional technology. Therefore, the "UHM process" is a useful technology to achieve further miniaturization of electromagnetic devices. In addition, the microminiature motors which used this technology have already been mass-produced.
