Toward High Energy Product Nd-Fe-B Magnets

Developments in the field of high-energy Nd-Fe-B magnets are reviewed and discussed. The highest value of the maximum energy product (BH)max reported so far for sintered Nd-Fe-B magnets is 416 kJ/m³ (52 MGOe), while a (BH)max of 360 kJ/m³ (45 MGOe) has been realized in commercial production. The highest (BH)max value obtained by means of rapid solidification and got-pressing processes is around 380 kJ/m³ (48 MGOe). Rapidly solidified isotropic magnets with high squareness are also described.