High Density, Multi-Layered Nosetips for Hypersonic Projectiles

The Navy is developing weapon systems capable of launching inert projectiles for long-range surface fire support and missile intercept applications. Inert projectiles offer significant logistical and safety advantages over conventional chemical propellants or explosive ordnances. The launch conditions of future hypersonic projectiles will put extreme mechanical and aerothermal loads on the projectile nosetip. These conditions combined with the high-density requirements present a significant materials challenge. No economical monolithic component is projected to survive the extreme conditions immediately after projectile launch, followed by less severe conditions during flight to target. The objective of a Phase II effort is to further the development of multi-layered nosetip concepts. This concept is based on a dense W core with outermost sacrificial layer that is intended to dissipate absorbed thermal energy from aerothermal loading, thereby limiting steep thermal gradients in the underlying refractory material(s). The team of Plasma Processes, MR&D and St. Croix Research will seek to build on Phase I efforts by optimizing materials selection, thermo-structural models, nosetip geometries, and fabrication techniques. At the conclusion of the base Phase II effort, nosetip specimens will be fabricated for testing in relevant arc jet environments. Testing will be conducted during efforts following the base Phase II.