Energy Partitioning and Microstructural Observations Related to Perforation ofTitanium and Steel Targets

摘要

This report presents an analysis of two target materials and the associatedenergetics related to the initial penetration into the target and perforation as the penetrator exits the target. Impact tests were conducted for tungsten alloy (WA) rods, striking rolled homogeneous armor (RHA), and titanium alloy plates. Rod-impact velocities were nominal 1,500 and 2,000 m/s. Target thicknesses were chosen so that the rods would overmatch the targets and lose some 200 m/s during penetration. The tests utilized flash x-rays to determine rod residual lengths and velocities and target plug features, to include thicknesses and velocities. From these observables, experimental determination of the corresponding kinetic energies (KEs) and estimates for the fracture energies were obtained. Also, in each case, target material adjacent to penetration-channel walls was examined by optical and electron microscopy and x-ray diffraction to gain further insight into deformation processes (cavity expansion) during penetration. The analytic penetration model gave results that were in good agreement with the experimental observables. In addition, it was observed that the RHA follows traditional plastic flow of cavity expansion, while WA shows deformation features that deviate significantly. The report discusses possible causes for these differences.