Self-sharpening behavior during ballistic impact of the tungsten heavy alloy rod penetrators processed by hot-hydrostatic extrusion and hot torsion

Tungsten heavy alloy (WHA) rod penetrators processed by hot-hydrostatic extrusion and hot torsion (HE + HT) are subjected to ballistic impact, and the as-sintered and the as-extruded WHA rod penetrators are tested for comparison. The HE + HT WHA penetrators display the best penetration performance with the critical minimum penetration velocity decreasing more than 9% and 5% compared with the as-sintered and the as-extruded WHA penetrators, respectively. The remnants of the as-sintered and the as-extruded WHA penetrators exhibit obvious mushroom-like heads, but the remnants of HE + HT WHA penetrators maintain an acuate shape, indicating a good self-sharpening ability. Microstructure analysis shows that, adiabatic shear bands (ASBs) form at edges of the HE + HT WHA penetrator heads during the penetration process, and deformed parts of the penetrators fall off along the ASBs, which are responsible for the good self-sharpening ability and evidently improved penetration performance. (C) 2010 Elsevier B.V. All rights reserved.