Interaction domains in die-upset NdFeB magnets in dependence on the degree of deformation

The magnetic domain structure of NdFeB magnets has been studied using high resolution, digitally enhanced Kerr-microscopy. Melt-spun NdFeB powder (MQU-F(TM)) was hot pressed into fully dense samples and then hot deformed to axially textured magnets. Various degrees of deformation ( height reduction) up to 76% have been realized. Pronounced interaction domains have been observed only in magnets, which were deformed to a degree of deformation of at least 52%. With increasing alignment of the grains the interaction domains become more and more visible and their size increases. (C) 2003 Elsevier B. V. All rights reserved.