GROWTH OF CRYSTALS FROM AMORPHOUS-ALLOYS

The paper gives a discussion on the kinetics of crystal growth during devitrification of amorphous alloys. Two examples of kinetic analysis of crystallization are reported: (a) a complete Johnson-Mehl-Avrami tr eatment of isothermal differential scanning calorimetry (DSC) peaks co mbined with microscopy observations provide a full set of kinetic para meters for Al91Nd9; (b) a mechanism for the formation of nanocrystals in Fe74Nb3Cu1Si13B9 is advanced on the basis of X-ray diffraction meas urements of the lattice parameter and isothermal DSC traces. A collect ion of the Arrhenius parameters for the rate of growth of crystals fro m amorphous alloys is presented and a correlation between them is show n The correlation is of the same type of that earlier found for tracer diffusion and suggests a cooperative mechanism for atomic movements l eading to the growth of crystals.