A.M. Molodets A.A. Golyshev, A.N. Emelyanov, A.A. Kozlov The method for recording magnetic transformation is presented for ferromagnetic steels under shock-wave loading. The operation of the magnetic transformation gauge is considered under shock-wave loading at the polymorphic transition pressure of ARMCO iron and 15Kh2NMFA (in Russian) nuclear reactors case steel. It is shown that the pressures of magnetic transformations of steels correlate with the pressures of polymorphic transitions of these shocked steels. Comparison of gauge readings and parameters of polymorphic transitions was performed for iron and steel during shock-wave compression and subsequent unloading

Modification of the semiempirical description of the volume-temperature dependence of the electrical conductivity and thermal conductivity of alpha-iron (iron having a body-centered cubic lattice structure) is presented. The interpolation of the volume-temperature dependences of the resistivity and thermal conductivity of alpha-iron along high-temperature isobars and high-pressure isotherms in the pressure range from -5 GPa to +5 GPa and temperatures of 400-800 K is considered for the conditions of normal and emergency operation of iron alloys. The interpolation of the electro-and thermophysical properties of alpha-iron is performed on the basis of the developed equation of state of alpha-iron at high pressures and temperatures. the effect of compression and tensile pressure on the thermal conductivity of alpha-iron is estimated.

AbstractThe spall strength and dynamic yield stress of polycrystalline hafnium have been measured in a series of plane-wave shock loading experiments using flat sample–transparent window composite targets, with the transparent windows representing polymethyl methacrylate or lithium fluoride plates arranged on the rear side of a hafnium sample. The front side of the target was subjected to shock impact of a copper striker, the rear surface velocity was measured, and the sample was recovered for subsequent metallographic examination. The results were also used for evaluation of the accuracy of spall strength measurements and the analysis of features of high-rate deformation of hafnium.

he spall strength of hafnium heated by a loading shock wave to thousandths of temperatures and subjected to transformation into denser polymorphic modifications has been determined. The following problems are solved. The pressure profiles at the sample-soft barrier interface in the spall experiments with flat one-dimensional loading are measured. The equations of state of three polymorphic modifications of hafnium are constructed in the pressure range up to 100 GPa. The thermodynamic states of hafnium under the conditions of the performed experiments were calculated. These calculations, together with the results of measurements of pressure profiles, made it possible to determine the spall strength of hafnium heated in a shock compression-unloading cycle. The spall strength of hafnium was -4 (1) GPa at a temperature of 1680 (380) K. Mathematical modeling of spall experiments in the framework of a one-dimensional hydrocode was performed.

The volume dependence of the band gap for aluminum hydride (alane) is compared at high static and dynamic pressures. Room temperature high pressure isotherm data and multiple-shock conductivity data were used for the reconstruction of the volume dependence of the alane band gap in the pressure range 50-75GPa. The traditional exponential relationship for the temperature dependence of semiconductor conductivity with the power law volume dependence of the aluminum hydride band gap is suggested in the regions of volumes 11.5-12.5cm3/mol, pressures 50-75GPa and temperatures 1270-1370K.

The experimental multiple-shock technique and a computer-code simulation were used for investigations of electrophysical properties of dense molten sodium up to pressures of 230(5) GPa and temperatures up to 8000(600) K. The multiple-shock data show that the resistivity of shocked sodium increases with pressure and temperature up to 270(30) mu Omega cm. This change was interpreted via the pressure-induced metal-semiconductor transition in shocked molten sodium.

C60 fullerite has been Ca-intercalated under high pressure up to 240 kbar induced by a shock-wave. Conductance of the samples exposed to shock-wave pressure has been measured. Magnetometric measurements have revealed superconductivity of the intercalated samples at 4.7, 9.9, and 30 K.

The electric resistance of shock-compressed scandium has been studied up to pressures of $90\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. The low-pressure phase of scandium Sc-I undergoes polymorphic transformation in the high-pressure incommensurate phase Sc-II at a shock pressure of $\ensuremath{\approx}16.5\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$ and a calculated shock temperature of $\ensuremath{\approx}510\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The equation of state of the incommensurate phase Sc-II is constructed.