Tungsten Composite Self-Forging Fragmenting Warhead

Fragmenting warheads offer a high kill radius and lethality against lightly armored targets such as aircraft, personnel carriers, entrenched personnel, missiles, and spacecraft. Increasing the density and controlling the size, shape, and velocity of the fragments can greatly increase warhead lethality and standoff capabilities through an approach called a self-forging fragmenting warhead, which combines explosively formed penetrator and fragmenting munitions technology. Further extension of this technology requires the development of small EFPs that produce fragments with high ballistic coefficients and stability, meaning high sectional density, fin-stabilized projectile formation. Tungsten is one of (if not the) most attractive materials for this purpose, being low in cost and having a higher density than depleted uranium or tantalum. However, while finned EFPS have been demonstrated by wave-shaping in tantalum, copper, and steel, conventional tungsten and tungsten heavy metal alloys possess insufficient ductility below 1000 C to form high L/D finned projectiles. As a result, current tungsten self-forging fragmenting warhead designs have poor material yield (material actually formed into the penetrator rod or ball), and no high L/D or finned tungsten EFPs have yet been developed. In this Phase I project, Ultramet proposes to demonstrate the feasibility of producing tungsten heavy metal composites having sufficient ductility for finned EFP formation, and fabricating tungsten EFP designs showing fin formation. Specifically, micron and submicron grain size tungsten heavy metal composites will be developed having optimal, non-equilibrium microstructures in nickel-iron and iron matrices, and initial EFP lens designs will be developed leading to finned tungsten.