in the case of ductile materials the milling performance is improved by embrittling the material. An usual way is milling under liquid nitrogen. For some metals (e.g. Nb) also the production sequence hydrating, milling de-hydrationg) works quite well.
If you can design a device that can scale centrifugal atomization production on large quantities as shown in the article below, it would be an outstanding method.
Article Production of fine calcium powders by centrifugal atomizatio...