Microsecond timescale combustion of aluminum initiated by an underwater electrical wire explosion

We report a direct observation of the microsecond time scale combustion of aluminum realized in underdamped electrical explosions of aluminum wires in the water environment. Experiments were conducted using a pulse power generator delivering a <= 200 kA current amplitude within an similar to 1 mu s rise-time. Time-resolved spectroscopy was applied to obtain the spectrum of AlO oxide absorption bands, and the temperature of oxides was determined. The results show that decreasing the wire diameter and increasing the discharge current density allow one to decrease the time delay in the appearance of AlO absorption bands to <= 1 mu s with respect to the beginning of the wire explosion and significantly increase the rate of aluminum combustion up to similar to 1.3 x 10(3) g/s.