Crystallization of Fe₈₃B₁₇ amorphous alloy by electric pulses produced by a capacitor discharge

Heating of conductive materials by electric current is used in many technological processes. Application of electric pulses to metallic glasses induces their fast crystallization, which is an interesting and complex phenomenon. In this work, crystallization of the Fe₈₃B₁₇ amorphous alloy induced by pulses of electric current produced has been studied using X-ray diffraction and transmission electron microscopy. Ribbons of the alloy were directly subjected to single pulses of electric current 250 µs long formed by a capacitor discharge. As the value of ∫I²dt was increased from 0.33 to 2.00 A² s, different crystallization stages could be observed. The crystallization began through the formation of the nuclei of α-Fe. At high values of ∫I²dt, α-Fe and tetragonal and orthorhombic Fe₃B and Fe₂₃B₆ were detected in the crystallized ribbons with crystallites of about 50 nm. Thermal annealing of the ribbons at 600 °C for 2 min resulted in the formation of α-Fe and tetragonal Fe₃B. It was concluded that pulses of electric current produced by a capacitor discharge induced transformation of the Fe₈₃B₁₇ amorphous phase into metastable crystalline products.