Low temperature crystallization of amorphous alloys under electropulsing

Abstract The crystallization under electropulsing was studied for amorphous (a-) Zr 60 Cu 30 Al 10 , a-Cu 50 Ti 50 and a-Pd 80 Si 20 using the discharge of a condenser, with an initial current density, i d0 of ∼10 9 A/m 2 and a decay time, τ , between 2 and 0.1 ms. The crystallization proceeds when i d0 increases beyond the threshold i d0,c . i d0,c shows a minimum value at τ ∼1 ms, where the maximum increase in temperature is lower than 120 K. We surmise that density fluctuations exist in amorphous alloys and that a high density region undergoes a resonant collective motion under electropulsing, which induces a migration of atoms in the low density matrix around it. On the other hand, the electrical resistivity, R , decreases in the early stages of crystallization due to electropulsing, and then increases with increasing i d0 suggesting that electropulsing also modifies the thermodynamic free energy of the phases.