Experimental measurements of the strength of metals approaching the theoretical limit predicted by the equation of state

The approach to the ultimate strength of metals is determined experimentally. The ultimate strength of metals was calculated using a realistic wide-range equation of state. The strength of metals was measured using shock waves created in aluminum and copper foils with a short- (20-100 ps) pulse high-power laser. The strength of the materials was determined from the free-surface-velocity time history, which was measured with an optically recording velocity interferometer system. The strain rates in these experiments were in the range (1.5-5)x10(8) s(-1). (C) 2000 American Institute of Physics. [S0003-6951(00)03112-0].