| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sintered magnet mass-producible and having an excellent magnetic characteristic by making the areas of crystal grains whose diameters are a specific value or more to the total area of the main-phase crystals of a magnet a specific value or more, the sum of the areas of crystal grains whose diameters are a specific value or less in a specific range, and magnetic characteristics Br, iHc specific values or more. SOLUTION: Ingots wherein RE-B-M-T are adjusted into various composition are manufactured, and they are finely ground into various average grain sizes after their coarse grinding. Two ingots having the same composition are ground into crystal grain diameters 4.3 and 5.2 microns, and they are mixed by a ratio of 50 to 50. The average grain size after the mixing is 4.7 microns, and the main-phase area ratio (%) after sintering is 50% or more for crystal grain diameters of 15 microns or more, and in a range of 2-5% for crystal grain diameters of 5 microns or less. Besides, its magnetic characteristics are in ranges Br>=12.8kG and iHc>=16kOe . By controlling the main-phase crystal grain diameter after sintering in this way, it becomes possible to obtain a high- performance magnet of high Br and iHc. |
