PROCESS FOR PRODUCING PERMANENT MAGNETS AND PRODUCTS THEREOF

摘要

Process for Producing Permanent Magnets and Products Thereof A process for producing permanent magnet materials, which comprises the steps of: forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, and the balance being Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200.degree.C, subjecting the sintered body to a primary heat treatment at a temperature of 750-1000.degree.C, then cooling the resultant body to a temperature of no higher than 680.degree.C at a cooling rate of 3-2000.degree.C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700.degree.C MGOe, 40 MGOe, or higher energy product can be obtained with specific compositions.