Tungsten-heavy alloy ballistic rod penetration into a copper target: microstructural analysis and computer simulations

摘要

The residual penetration of an OFHC copper target impacted by a tungsten-heavy alloy (WHA) long-rod projectile at a striking velocity of 1.5 km/s, has been analyzed by metallography, SEM, TEM and microhardness testing to characterize microstructures produced by the cylindrical shock-wave geometry initiated at impact. A narrow zone of dynamically recrystallized grains at the edge of the crater is responsible for the flow of copper material and subsequent perforation by the projectile; this is also evidenced by the fragments of WHA embedded along the channel wall. TEM analyses, along with selected-area diffraction, reveal the presence of deformation twins and microbands, as well as an intermixing of both. Computer simulations of the ballistic event have been performed with the purpose of comparing residual stress maps to the experimental microhardness analysis in an attempt to establish a microstructure-based validation to augment the penetration geometry and rod erosion comparison.