The Investigation of the Magnetization Reversal Mechanism in the Nd-Fe-B Type Magnet, Aligned by Hot Deformation

The magnetization reversal mechanism in the $Nd_{16}Fe_{78}B_6$ hot densified magnet, aligned by means of die-upset forging has been investigated. The magnetic parameters have been derived from major hysteresis loop. The magnetocrystalline anisotropy constants $K_1$ and $K_2$ using Sucksmith-Thompson relation modified by Ram and Gaunt have been calculated from the high field measurements up to 5 T. These data have been used to determine the theoretical value of coercivity as a function of the angle $Ψ_0$ between the sample easy axis and the applied magnetic field direction. The experimental value of coercivity as a function of $Ψ_0$ has been determined from the demagnetization curves measured for different $Ψ_0$ angles. It was found that the best correlation between theoretical and experimental data have been achieved for magnetization reversal mechanism controlled partially by pinning of domain walls on grain boundaries and nucleation processes.