The ball to powder ratio (BPR) dependent morphology and microstructure of tungsten powder refined by ball milling

The graphical abstract shows the powder refinement process and its schematic diagram. The changes of particle size with different BPR at different milling time was also shown. The nanocrystalline tungsten powder with grain size ranging from 5-15 nm was successfully fabricated by ball milling with the BPR of 15:1.226