Deformation of armco iron and copper at strain rates of 10$^4$–10$^5$ sec$^{-1}$

Studies were made of the structural and strength variations in tubular specimens of Armco iron and copper after separation caused by explosion loading at strain rates of 10$^4$–10$^5$ sec$^{-1}$ up to a specified degree of deformation. In Armco iron the transition to adiabatic shear occurs under considerably more severe loading conditions than in strong steels. In macrocrystalline copper for the most severe of the loading parameters attained, conditions for the beginning of adiabatic shear were not reached. An unusual failure mechanism was observed: the formation and growth of several macroscopic pores at triple junctions of the grains.