METHOD FOR PREPARING RARE-EARTH PERMANENT MAGNETIC MATERIALS

A method for preparing rare-earth permanent magnetic materials, comprising the following steps : selecting a sintered neodymium iron boron (NdFeB) blank, a waste NdFeB magnet or NdFeB scrap after washing and stoving, breaking same down into NdFeB powder; applying an oriented magnetic field to the NdFeB powder to turn the latter into a NdFeB green part; placing the NdFeB green part within the cavity of a pressure sintering mold, the pressure sintering mold being in a hermetically sealed space, under a vacuum or the protection of insert gas, heating and pressurizing to perform the pressure sintering, and then cooling and taking out; placing the pressure-sintered magnet within a vacuum furnace to perform heat treatment for secondary tempering, and obtaining a NdFeB magnet. The method has advantages of good magnetic powder flowability, high production efficiency, small product deformation and less crack; the oriented magnetic field is low, and a stable mass production of special oriented magnet such as a radiation ring can be realized; pressure sintering is performed by using the pressure sintering mold, the dimensions of the magnet are approximate to the dimensions of a final finished product, the material utilization and the magnetic property are high, and cost is low.