Effects of alignment on the magnetic and mechanical properties of sintered Nd–Fe–B magnets

Abstract Sintered Nd–Fe–B magnets with various degrees of grain alignment are prepared by the conventional powder metallurgy technique. The magnetic properties, bending strength and fracture morphologies of sintered magnets with different alignment degrees are investigated. The results show that the remanence B r and maximum energy product ( BH ) max increase, while intrinsic coercivity H cj decreases gradually with increasing the alignment degree. Moreover, the bending strengths measured by applying force parallel ( σ bb∥ ) and perpendicular ( σ bb⊥ ) to the alignment magnetic field H appl present opposite variation tendency, and σ bb∥ is larger than σ bb⊥ , suggesting the more significant anisotropy of mechanical properties with increasing the degree of grain alignment. Furthermore, the related mechanisms are systematically analyzed.