Two-phase microstructure in Pr-(Fe, Co, Ni)-B sintered magnets

Abstract A search was carried out for a two-phase sintered magnet comprising Pr 2 TM 14 B and PrTM, where TM stands for Fe, Co and Ni. Specimens were prepared by a powder metallurgical method using alloys with compositions Pr 17 (Fe 0.6 Co 0.3 Ni 0.1 ) 83 − χ B χ ( x = 4, 5 and 6). X-Ray diffraction and scanning electron microscopy—energy-dispersive X-ray studies have revealed that two-phase magnets are realized for Pr 17 (Fe 0.6 Co 0.3 Ni 0.1 ) 78 B 5 . The microstructures of these sintered magnets are characterized by Pr 2 TM 14 B grains surrounded by an intergranular Ni-rich PrTM phase whose thickness is less than about 3 μ.