METHOD FOR PREPARING HIGH-ORIENTATION-DEGREE SINTERED NEODYMIUM-IRON-BORON PERMANENT MAGNET MATERIAL BY MEANS OF WET-PRESS FORMING

摘要

The present invention relates to the technical field of rare earth permanent magnets, and provides a method for preparing a high-orientation-degree sintered neodymium-iron-boron permanent magnet material by means of wet-press forming: making neodymium-iron-boron powder particles and an organic solvent into a slurry and pouring the slurry into a mold with a double-layer structure; carrying out orientation profiling in a magnetic field, carrying out orientation and extrusion at the same time, and after a large amount of liquid is drained, obtaining a high-orientation-degree blank body with certain density; and finally, performing isostatic pressing, sintering densification, and tempering thermal treatment to obtain the high-orientation-degree sintered neodymium-iron-boron permanent magnet material. According to the method, the mold is of the double-layer structure, an inner layer is a mold wall with evenly distributed submicron pores, an outer layer is a mold wall with larger holes, and the inner mold wall and the outer mold wall are closely attached; in addition, the slurry formed by the neodymium-iron-boron powder and the organic solvent is high in mobility and can easily be oriented in the magnetic field; moreover, by gradually discharging the solvent out by extruding of a mold extruding head, full orientation can be guaranteed, and a blank body with high density can be obtained to facilitate subsequent procedures after the liquid is drained; the method is simple and easy to execute and has a wide application prospect.