Dynamically Determined Pressure‐Volume Relationships for Aluminum, Copper, and Lead

摘要

This work presents experimentally determined pressure‐volume data for copper to 116 kbars, lead to 78 kbars, and 1060 aluminum to 39 kbars. At these low stresses, the shear strength cannot be ignored; therefore, the dynamic stress‐strain curves are reduced to Hugoniot form for further correction to ``shock hydrostats.'''' These data may be compared to either isothermal hydrostatic data or to ultrasonic and very high‐pressure dynamic data. In the former, polynomial pressure‐volume data fits are corrected thermodynamically to isothermal conditions through the Grüneisen equation of state. Copper and aluminum dynamic curves are in reasonable agreement with the Bridgman curves; lead, on the other hand, shows marked discrepancies. In the latter comparison, the pressure‐volume data are reduced to a bulk shock velocity and particle velocity plot. These data fit smoothly with the very high dynamic pressure data. Copper gives a linear fit, aluminum a quadratic fit, and lead does not permit distinction between a linear or quadratic fit. Agreement between dynamic and ultrasonic data is extremely good and suggests high accuracy for the dynamic data.