Study of Microstructure and Magnetic Properties of Pr-Fe-B-Cu Permanent Magnets by Hot Deformation

摘要

The relationship between the microstructures and magnetic properties of rare earth cast permanent Pr Fe B Cu alloys by hot deformation was studied. Fine and well aligned column grains can be obtained by using a proper solidification mould with a high cooling rate. The soft magnetic phase α Fe can be removed during proper annealing treatment. Hot pressing can produce the anisotropy and refine the grain size, so that the magnetic properties are greatly improved. The technique has the advantages of simple processing, low cost and high benefit, compared with the common sintering processing. Under the condition of the deformation temperature of 1073 K, 90% strain and strain rate of 40×10 -3 s -1 , the magnetic properties obtained are: B r=1.05 T, i H c=955 kA·m -1 , ( BH ) max =207 kJ·m -3 .