Microstructural evolution of commercial Ti and Zr powders upon mechanical m
illing was characterized by means of X-ray diffraction, scanning electron m
icroscopy and transmission electron microscopy. Evident structural inhomoge
neity was observed upon milling the two commercial powders. A partial amorp
hous state was attained in Zr after 100 h of milling. The possible origins
for the amorphous phase formation were discussed.