Effects of post-sintering annealing on magnetic properties of Nd–Fe–B sintered magnets

Phase transformations and coercivity in rare-earth permanent magnets

“…The phase transformation-induced coercivity mechanism for Nd-Fe-B sintered magnets was suggested earlier [7]. The model of interface modification by HT is based on the phase precipitation at the surface of Nd 2 Fe 14 B grains that is caused by the eutectoid decompositions within the intergranular Nd-rich layers.…”

Heat treatment, microstructure and coercivity of (Nd, Dy)-Fe-B based permanent magnets

“…To explain the above results the hypothetic metastable Fe-Nd phase diagram was suggested [5]. At the right side of Fig.…”

Coercivity Enhancement of Sintered Nd–Fe–B Magnets by Intergranular Adding Micro-Structured Dy–Nd–Pr–Al–Cu Powder

“…The mixing time of powder mixture was 1 h. The mixed powder was compressed, with a pressure of 15 MPa, into rectangular parallelepiped tablets (7 © 5 © 3 cm 3 ) in oriented magnetic field of about 20 kOe yielded by an electromagnet. The pressed magnet tablets were then sintered at 1080°C for 1 h in vacuum and subjected subsequently to two-stage heat treatment at 820°C for 1 h and at 540°C for 1 h. 27,28) For both the stages, the magnets were fast cooled down to room temperature by Ar gas. The structure of the materials was thoroughly analyzed by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) techniques.…”