Stepwise shock compression of aluminum at room and elevated temperatures

With the aim of expanding the measurable range of high-rate deformation, experiments were conducted in which AD1 aluminum [A199.3 under the international classification and AA1135 in the USA (American National Standards Institute)] was subjected to stepwise shock compression at both room temperature and in the range of 498-530 °C. Measurements of the width of the plastic shock waves revealed that the anomalous thermal hardening at strain rates exceeding 10⁵ s^-1 is maintained upon increasing the deformation up to at least 6.5%. The hysteresis during shock compression and unloading cycles of the elastic-plastic body was analyzed. The results indicated that determination of the stress states behind the plastic shock wave utilizing this method requires higher than usual measurements and calculation accuracies.