Textured NdFeB HDDR magnets produced by die-upsetting and backward extrusion

摘要: The hydrogenation disproportionation desorption recombination (HDDR) process was applied to produce isotropic, submicron powder in 500 g batches a specially designed HDDR reactor. hot pressing characteristics of the material were determined and it shown that has an excellent stability against grain growth. coercivity 1000-1080 is almost constant over temperature range 700-, making highly suitable for subsequent deformation. Die-upset magnets prepared order study basic deformation behaviour. A remanence 1.13 T axial direction achieved. Similar properties obtained backward extruded produced at only small decrease alignment along ring found. Grain sizes very uniform on scale. Platelet-shaped grains observed die-upset magnets. formation interaction domains, radial directions respectively, established by high-resolution Kerr microscopy. high degree texture deformed also confirmed Lorentz microscopy revealing continuous equispaced domains extending entire thinned sample with directional variations.