Ultra-fine grained Nd-Fe-B by high pressure reactive milling and desorption

► High pressure reactive milling (HPRM) reduces the grain size below 70 nm. ► HPRM reduces the recombination temperature by about 200 °C in comparison to d-HDDR. ► Anisotropic d-HDDR powders show a large degree of texture (DOT). ► Alignment of anisotropic particles was improved by a 2nd preparation technique.