| abstract |
There is disclosed a R-Fe-B or R-Fe-Co-B alloy permanent magnet powder which may contain Ga, Zr or Hf, or may further contain Al, Si or V. R stands for a rare earth element including yttrium. Each individual particle of the powder includes a structure of recrystallized grains containing a R 2 Fe 14 B or R 2 (Fe,Co) 14 B intermetallic compound phase. The intermetallic compound phase has recrystallized grains of a tetragonal crystal structure having an average crystal grain size of 0.05 to 20µm. At least 50% by volume of the recrystallized grains of the aggregated structure are formed so that a ratio of the greatest dimension to the smallest dimension is less than 2 for each recrystallized grain. In order to manufacture the magnet powder, regenerative material and alloy material are prepared and their temperature is elevated in a hydrogen atmosphere. Then, the alloy material and the regenerative material are held in the same atmosphere at a temperature of 750°C to 950°C, and then held in a vacuum at 750°C to 950°C, and cooled and crushed. A bonded magnet produced using the above magnet powder is also disclosed. |