A METHOD FOR PRODUCING A RARE EARTH METAL-IRON-BORON ANISOTROPIC SINTERED MAGNET FROM RAPIDLY-QUENCHED RARE EARTH METAL-IRON-BORON ALLOY RIBBON-LIKE FLAKES

摘要

In a method for producing a rare earth metal-iron-boron (R-Fe-B) anisotropic sintered magnet from R-Fe-B alloy ribbon-like flakes, each flake is formed with a thickness of about 20-500 νm and contains R2Fe14B crystal grains dispersed in the flake with an average grain size of 10 νm or less. The flakes are ground into a powder having an average particle size less than the thickness value of the flake. The powder is magnetically aligned and compacted into a compact body which is then sintered. Thus, the anisotropic sintered magnet is obtained with a high energy product and a high anti-corrosion property. The ribbon-like flakes are prepared by the continuous splat-quenching method. Alternatively, the flakes can be prepared by spraying the molten R-Fe-B alloy in a form of particles and cooling the particles on a cooling plate into flat small pieces.