Strength and elasticity of iron and copper at high shock-wave compression pressures

The elastic and strength parameters of iron and copper were determined experimentally at high shock-wave compression pressures of 1–2 Mbar. The attenuation of shock waves created by the impact of thin plates in blocks of the investigated materials was recorded in the experiments. The Poisson ratios, bulk moduli, shear moduli, and yield strength Y for iron at 1.11 and 1.85 Mbar and for copper at 1.22 Mbar were determined from the experimentally observed amplitudes and velocites of the unloading shock waves. The shape of the curve of the change of the yield strength of copper with an increase of pressures to states of shock-wave compression causing melting was determined on the basis of the results obtained and data of other investigators. The curve has a maximum at P 800 kbar corresponding to Y =280 kg/mm². The yield strengths for iron are located on the ascending branch of the curve Y(P) and are numerically equal to 110 kg/mm² at 1.11 Mbar and 270 kg/mm² at 1.85 Mbar. The measured values of Y exceed the yield strengths of uncompressed metals by a factor of 5–7. The authors also recorded a substantial increase of Poisson's ratios with increase of pressures in the investigated metals.Deceased.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 6, pp. 159–166, November–December, 1971.