The mechanism of magnetic alignment in hot rolled Nd–Fe–B magnets

Abstract The establishment of magnetic alignment, also called magnetic texture, and its dependence on process parameters was studied on hot rolled and heat-treated Nd–Fe–B magnets. Results showed that texturing is a consequence of fracture of the magnetic phase and subsequent rearrangement of the debris. Although the extent of magnetic alignment is related to both rolling temperature and post-deformation heat treatments (it normally increases with these operations), the relationship between the direction of the easy magnetization axis of the Nd 2 Fe 14 B magnetic phase and the deformation direction is also important. Thus, an ingot with a well-developed initial texture may have its magnetic alignment decreased by rolling, but on the other hand, this alignment will be always higher than the one achieved by a rolled ingot with a less-developed initial texture. Finally, a suitable treatment of the X-ray data allowed the theoretical calculation of remanence values which compared favourably with the experimental ones