CRYSTALLIZATION OF AN MG74ZN26 GLASS

Useful amounts of amorphous Mg100-xZnx alloys, with x lying in the range 24-32, have been prepared by splat quenching in a vacuum using the gun technique. The apparent activation energy for crystallisation of a splat-quenched Mg74Zn26 glass was 160 kJ/mole indicating that the rate of crystallisation scaled as the viscosity. Crystallisation involved the formation of a fine-grained Mg7Zn3 phase having an excess of Mg. The subsequent recrystallisation reaction giving a more perfect Mg7Zn3 phase was accompanied by the precipitation of the excess Mg. The apparent activation energy of the combined processes was 120 kJ.mole, equal to the activation energy for interdiffusion in an equilibrated Mg7Zn3 compound. © 1978.