Texture inducement during HDDR processing of NdFeB

The microstructural changes during the hydrogenation disproportionation desorption recombination process have been characterized step by step. The magnetic properties and the degree of texture have been determined when varying the hydrogen pressure and a strong correlation was found: low hydrogen pressure during disproportionation yields an excellent degree of texture. Detailed electron microscopy revealed complex microstructures and, most importantly, we found crystallographically correlated Fe2B grains within the disproportionated material and we propose the latter phase as the anisotropy-mediating phase throughout the different stages. This mechanism is highly stable provided the appropriate hydrogen pressure is employed.