Electrical resistance of aluminum under shock compression: experimental data

Experimental data on the electrical resistance of aluminum under shock compression are analyzed. The electrical resistance of two types of aluminum foil located in dielectrics with different shock impedances is measured by the electrical contact method. The resultant dependences of the electrical resistance of aluminum on the shock wave pressure are monotonically increasing functions of pressure. However, the dependence of the specific electrical resistance of aluminum on the shock wave pressure can be monotonic (foil in Plexiglas) or nonmonotonic (foil in fluoroplastic). In the latter cased, the specific electrical resistance first slightly decreases with an increase in pressure and then increases. This behavior can be explained by the competing effects of compression and temperature heating on the specific electrical resistance. Due to shock compression of metal foil in the dielectric with a smaller shock impedance (Plexiglas), the measured electrical resistance is greater than that in the dielectric with a greater shock impedance (fluoroplastic). This result is caused by the greater temperature heating of metal foil in Plexiglas. The reasons for the qualitative difference in the behavior of the specific electrical resistance of metal under static and dynamic compression are discussed.