MANUFACTURE OF ANISOTROPIC OXIDE PERMANENT MAGNET

PURPOSE:To make anisotropic oxide magnetic material possible to easily respond to a demand for high magnetic characteristic by gradually raising the temperature of sintering the anisotropic oxide magnetic material at a temperature rising rate ranging from 20 to 150 deg.C/H in a temperature range of 900-1100 deg.C that is for the initial stage of sintering. CONSTITUTION:In addition to the control of the magnetic characteristic of oxide magnetic powder by controlling the composition of the oxide magnetic powder, particularly the composition of a very small amount of additive and by controlling the temperature of baking the magnetic powder, the magnetic powder is baked at a temperature rising rate of 20-150 deg.C/H in a temperature range of 900-1100 deg.C that is the temperature range for the initial stage of sintering to prepare anisotropic oxide permanent magnetic having high magnetic characteristic. In other words, by gradually raising the baking temperature at a rising rate of 20-150 deg.C/H in a temperature range of 900-1100 deg.C that is for the initial stage of sintering, a very small amount of the component (additive) in the magnetic material is concentrated uniformly in a grain boundary. As a result, since the grain sizes of crystal particulates are really equal to each other without growing to large sizes, the magnetic powder is provided with high magnetic characteristic. With this, anisotropic oxide permanent magnet superior in magnetic characteristic can be easily and purely produced.