Magnetic Properties of Nd-Fe-Co-Cu-Nb-B System Exchange Spring Magnets

Abstract

Melt-spun ribbons of Nd-Fe-Co-Cu-Nb-B system alloys were prepared by the single-roller rapid-quenching method, and the effects of the composition, wheel velocity, and heat treatment on the magnetic properties were investigated. The optimum preparation conditions and some properties are as follows: composition, Nd₅Fe₇₁Co₅Cu_0.5Nb₁B_17.5; wheel velocity, 20 m/s; annealing conditions, 650°C ×10min in Ar atmosphere; magnetic propeties, J_r = 1.175 T, H_cJ = 342.6 kA / m, H_cB = 307.6 kA / m, (BH)_max=1 14.8 kJ/ m³, α(B_r) = -0.056%/°C, β(H_cJ) = -0.354%/°C.