High-Strength, Wear-Resistant Nanostructural Composites for Hard-Target Ballistic Penetrators

Hard-target weapons currently in development or being considered by DoD include a variety of ground-, ship-, and air-based target penetrators. The lethality of many of these systems are critically dependent on the ability to maintain geometric stability of the penetrator. A refractory, wear-resistant material may be essential for effective sand and earth ballistic penetrators. However, the need for high strength, high density, and in particular high toughness also exist. Most hard, wear-resistant materials are highly brittle ceramics, and are unsuitable for ballistic penetrators.The emerging field of nanostructured materials allows for desired material properties to be engineered into the composite material. Unique properties have been well documented in a wide variety of nanostructural systems, where the resultant mechanical properties far exceed the properties predicted by the simple rule-of-mixtures. High rate chemcial vapor deposition (CVD) is a promising and economically viable technique for producing nanostructural composite components via CVD. This program will examine the feasibility of producing dense tungsten/tungsten carbide (W/WC) nanostructural composties for hard-target ballistic penetrator nose-tip/nose-cap components. Nanostructured W/WC that contains only very thin (~10 nm) layers of tungsten carbide interspersed with slightly thicker layers of tungsten has already been demonstrated to possess strength and wear resistance that is far greater than either of the individual constituents. This Phase I program will demonstrate the feasibility of fabricating massive (thick) deposits of this nanolayered material. Properties such as hardness, wear resistance, fracture toughness, strength, and elastic properties will be empirically determined and correlated with nanocomposite microstructure to aid in optimizing the material for potential ballistic penetrator application.