Deformation behavior of platinum and alloy Pt-25% Ir under spherical shock waves

The data are presented on spherical explosion experiments on all-round squeezing of tight balls of Pt and alloy Pt-25% Ir with their further preservation. Calculated estimates of parameters of load pulses realized in the balls are given. The results of comparative study of high-speed plastic deformation mechanisms in unalloyed platinum and in the alloy on its base, obtained using methods of X-ray diffraction analysis, light metallography, scanning and transmission electron microscopy, as well as measurements of microhardness on a radius, are described. It is ascertained that high speed plastic deformation of these materials is mainly by way of intragrain slip that executes by several slip systems simultaneously, by way of partial grain-boundary slip which runs most intensively in platinum in the layers located at deep radii, as well as through formation of deformation vortices and localized deformation bands. It is noted that the difference in mechanical properties of unalloyed platinum and a Pt-25% Ir alloy observed under quasistatic tension is still retained during their high speed deformation by waves of megabar range and microsecond duration