The Metallographic Study of High-Speed Deformation and Convergence of Thick-Walled Cylindrical Copper Shells under Explosive Loading

Abstract—

Metallographic method investigated the process of convergence of thick-walled cylindrical copper shells under the action of an explosion. The explosion was initiated from eight points evenly spaced in a circle on the surface of the explosive surrounding the shell. At the intermediate stage of convergence, eight outliers formed on the inner surface of the shell. The convergence of the shells into the cylinder is completed by expanding and closing the emissions. The formation of outliers is explained by the occurrence of plastic (cumulative) jets at the deformation front. Jets occur when adjacent deformation projections collide. Areas of localized deformation were found inside and around the ejections, which is associated with this method of initiating an explosion. It is established that high-speed deformation of copper during the convergence of shells is accompanied by the formation of a large number of twins. There are more twins in the outer zones of the shells than in the inner ones.