Transient pressure analysis of exploding aluminum metallized films

The electrical explosion of 225A thin aluminum films has been studied. A set of experiments have been designed and executed to investigate the relationship between inductance in the discharge circuit path and the pressures produced by the explosion of the film. A piezoelectric pressure transducer has been utilized to report these pressures for several different inductance values. An inverse relationship between the inductance and the resultant pressures was established. A detailed analysis of the results was undertaken which showed that the first pressure peak was the result of the rapid phase change of the aluminum. The effect of the inductance caused later burst times which translated into lower overall pressures. The second pressure peak was found to be caused by the magnetohydrodynamic waves of the arc discharge plasma that forms during the current re-strike period. The relationship between the current and the magnetic field were validated by the results which showed the decreased current density at higher inductances caused lower second peak pressures. The relationship between inductance and pressure has laid the frame work for more application specific investigations which could include fusing, electronic detonation and initiators, ceramic plate joining, and thin-plate accelerators.