RARE EARTH ELEMENT-IRON-NITROGEN MAGNETIC MATERIAL CONTROLLED IN MICROSTRUCTURE, MANUFACTURE, AND MANUFACTURE OF POWDER WHICH IS ITS STOCK

摘要

PURPOSE:To improve magnetic characteristics by controlling the particle diameter, mixture of phases, and phase splitting of Re-Fe alloys prepared initially and by classifying them by every grade before composition of Re-Fe-N or Re- Fe-N-H-O magnetic materials. CONSTITUTION:Before composition of the base alloy of rare earth element-iron- nitrogen magnetic material, to average crystal particle diameter of the base alloy is adjusted to a range of submicrons to 300mum by controlling the cooling speed of molten metal and by varying the annealing temperature over a range of 700-1300 deg.C to time annealing at a duration where a phase consisting mainly of iron can be reduced to an allowable amount as the magnetic material. After preparation of rare earth element-iron alloy or composition of rare earth element-iron-nitrogen magnetic material powder, classification is conducted to sort out the powder of an arbitrary region of particle size distribution ranging from submicrons to 300mum.