EVIDENCE OF FRACTALS IN THE PRELIMINARY STAGES OF AMORPHIZATION BY MECHANICAL ALLOYING

The evolution of the amorphous phase in the solid state reaction of al loys with composition Fe67Ti33 was followed with neutron and X-ray sca ttering techniques in the case of metal powders treated by mechanical milling (MM) and by mechanical alloying (MA). The X-ray and neutron di ffraction data show that the milling time is related to the coordinate of reaction. In the case of neutron small-angle scattering, data anal ysis of the log I vs. log Q graphs suggests that the fractal concept i s useful in describing the earliest stages of the solid state amorphiz ation reaction.