This paper presents the results of measurements of the strength properties of technically pure tantalum under shock wave loading. It has been found that a decrease in the grain size under severe plastic deformation leads to an increase in the hardness of the material by approximately 25%, but the experimentally measured values of the dynamic yield stress for the fine-grained material prove to be less than those of the initial coarse-grained specimens. This effect has been explained by a higher rate of stress relaxation in the fine-grained material. The hardening of tantalum under shock wave loading at a pressure in the range 40–100 GPa leads to a further increase in the rate of stress relaxation, a decrease in the dynamic yield stress, and the disappearance of the difference between its values for the coarse-grained and fine-grained materials. The spall strength of tantalum increases by approximately 5% with a decrease in the grain size and remains unchanged after the shock wave loading. The maximum fracture stresses are observed in tantalum single crystals.

The results of measurements of the decay of an elastic precursor in iron at the distances from 0.13 to 10 mm and the spall strength of the samples with such thicknesses have been compared with similar data for the nanometer-scale samples. The decay has been described by a unique dependence whose differentiation gives the relationship between the initial plastic strain rate in the range from 10³ to 10⁹ s⁻¹ and the compression stress in the elastic shock wave from 1.5 to 27.5 GPa. The dynamic breaking strength (spall strength) varies in this range of shock-wave load time from 1.5 to 20 GPa.

This paper presents the results of measurements of the dynamic elastic limit and spall strength under shock wave loading of specimens of the magnesium alloy Ma2-1 with a thickness ranging from 0.25 to 10 mm at normal and elevated (to 550°C) temperatures. From the results of measurements of the decay of the elastic precursor of a shock compression wave, it has been found that the plastic strain rate behind the front of the elastic precursor decreases from 2 × 10⁵ s⁻¹ at a distance of 0.25 mm to 10³ s⁻¹ at a distance of 10 mm. The plastic strain rate in a shock wave is one order of magnitude higher than that in the elastic precursor at the same value of the shear stress. The spall strength of the alloy decreases as the solidus temperature is approached.

The results of measurements of the dynamic elastic limit and spall strength under shock-wave loading of aluminum samples AD1 of thicknesses between 0.5 and 10.0 mm at room temperature and at temperature increased up to 600°C are presented. The anomalous thermal hardening of aluminum under high strain rate has been confirmed. An analysis of the decay of precursors at temperatures of 20 and 600°C has shown that the change in the main mechanism of drag of dislocations occurs at a strain rate equal approximately to 5 × 10³ s⁻¹, which agrees with the results of measurements by the Hopkinson split bar method. The results of measurements of the spall strength in a wide range of strain rates add the previously obtained data and agree with them.

Elastic–plastic shock compression, unloading, and the stepwise shock compression of copper were investigated at room temperature, 710 °C, and 850 °C to expand the measurement range of high-rate deformations. The dependences of the dynamic yield stress on the temperature and pressure of shock compression were determined from an analysis of the free-surface velocity histories. Although the initial resistance to high-rate deformation increases anomalously with increasing temperature, even a small strain in the shock wave can change the sign of the temperature dependence of the flow stress. Using these data, the dependence of the plastic strain rate on the shear stress in shock waves and temperature was obtained in the range 10⁵–10⁷ s⁻¹. It was found that at room temperature, the ratio between the shear stress and the plastic shear strain rate in a shock wave practically does not depend on the loading history, whereas at 850 °C, the parameters of the plastic flow in the second shock wave deviates significantly from the initial dependence for lower stresses and higher strain rates.

Elastic–plastic waves of shock compression and unloading in annealed AD1 aluminum were recorded at room temperature, 508 °C, and 610 °C. Using measurements of the parameters of the plastic shock waves and quasi-elastic rarefaction waves at the peak shock stresses from about 1.5 to 4.2 GPa, the strain rate dependences on the stress, the temperatures, and the loading histories were obtained in the range of 10⁵–10⁷ s⁻¹. The initial resistance to high-rate deformation was found to increase anomalously with increasing temperature, but even a small deformation in the shock wave and the accompanying multiplication of dislocations changed the sign of the temperature dependence of the flow stress.