Discharge Modes of Electrical Explosion of Aluminum Wires in Argon

Electrical explosion of wires (EEW) can be utilized as an efficient method to prepare nanopowders of metal, metal oxide, metal alloy, and so on, and the behavior of exploding wires varies greatly with different load and circuit parameters. In this paper, the relationship between discharge modes of EEW and load parameters (length and diameter) was studied during the preparation of Al nanopowders via EEW in argon gas. The experimental results showed that with fixed wire length and increasing diameter, the EEW will successively show the feature of current pause, current dwell, current pause again, and finally 'being matched'; and for fixed wire diameter, there is a 'critical length' of wire which divides the current-dwell mode and the current-pause mode. The critical length as a function of wire diameter peaks between 0.2 and 0.3 mm for the charging voltage of 11.5-20 kV (2.6- μ text{F} capacitor); and the specific heat (deposited energy divided by sublimation energy) of wires was approximately 1 at the peaks.