METHOD FOR PRODUCING RFeB SINTERED MAGNET AND RFeB SINTERED MAGNET PRODUCED THEREBY

摘要

The purpose of the present invention is to provide a method for producing an RFeB sintered magnet in which the particle size of the main phase particles is 1 µm or less, the uniformity of particle size distribution is high, and a high degree of orientation is achieved. In the method for producing an RFeB sintered magnet, an RFeB alloy powder in which the average value for particle size distribution as analyzed from a microscope image using equivalent circle diameter is 1 µm or less is obtained by pulverizing coarse microparticles of crystal particles that have RFeB crystal particles formed therewithin and for which the average value of particle size distribution as determined from a microscope image using equivalent circle diameter is 1 µm or less, said RFeB alloy powder being in a state in which 90% or more of the crystal grains by area ratio are separated from one another, and the RFeB alloy powder is used to produce a material body that is oriented using a magnetic field. As a result of the crystal grains being separated from each other in the alloy powder, it is possible to produce an RFeB sintered magnet having a high degree of orientation.