AMORPHIZATION MECHANISMS OF NIZR2 BY BALL-MILLING

The microstructure of NiZr{sub 2} in the course of amorphization by ball-milling is studied by transmission electron microscopy and x-ray diffraction. The evolution from the initial fully crystalline alloy to a fully amorphized material is described. It is shown that prior to amorphization, the powder aggregates achieve a 100{percent} nanocrystalline structure, the amorphous phase then appears and develops to the expense of the nanocrystalline phase. No massive chemical disordering is observed but a small amount cannot be ruled out. It is proposed that amorphization occurs by chemical disordering at interfaces, induced by the scattering of shear waves. {copyright} {ital 1997 Materials Research Society.}