Dynamic stress-strain behavior of pure iron for shaped charge liners

The shock compression experiments of pure iron for shaped charge liners after annealing at 930℃ for 2 h were carried out with the split Hopkinson pressure bar apparatus, and its dynamic stress-strain relationships were measured at different strain rates. The microstructure of the deformed pure iron was examined by optical microscope. The microstructure evolution occurring at different strain rates and dynamic stress-strain behavior were investigated. It is shown that pure iron for shaped charge liners has the twinning structure after impact compression. The effect of work-hardening and strain rate strengthening for pure iron occurs at the strain rates of 650 to 3 850 s^-1, and the maximum strain also rises with increasing strain rate. Twinning and slipping are the plastic deformation mechanism of pure iron under the shock of high strain rate, which leads to the increase in both strength and plasticity at high strain rate for pure iron.