Thermal Protection Coating for Artillery Projectiles

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Hypersonics OBJECTIVE: Develop innovative conformal, ruggedized solutions for thermal protection of extended range artillery rounds. DESCRIPTION: The Army's Long Range Precision Fires mission expands the current portfolio of conventional artillery to advanced munition technologies with extended range capability (>70km). Extended range requires the projectile to fly to higher velocities and altitudes as well as longer flight times. At high Mach speeds the projectiles may be exposed to high temperatures and heat fluxes up to 3500 C and 1000 W/cm2 respectively. These are new environments to which conventional gun launched ammunition has not been subjected to. Along with qualifying artillery for new weapons platforms such as Extended Range Cannon Artillery (ERCA), they also have to survive the extended range environment. The Army is currently looking for novel thermal protection coatings for artillery shells in an effort to extend the capability of conventional ammunitions and enable integration of other aero-structural materials such as polymer matrix composites and high strength alloys. The proposed solution must be able to protect the underlying base material against high heat flux and high temperature damage. The technology should be capable of surviving typical artillery gun launch loads and should conform to the geometry of an artillery projectile. PHASE I: During the Phase I contract, successful proposers shall conduct a proof-of-concept study that focuses on thermal protection coating technologies that can withstand and operate within varying thermal loads ranging from 5 W/cm2 to 700 W/cm2 and temperatures ranging from ambient to 2000 F (objective) for up to 5 minutes (objective). Coating thickness should not exceed 5mm (objective) and can be ablative in nature so long as sufficient thermal protection is sustained to meet the objectives. Investigations should include analysis of material performance under transient thermal loading and thermos-structural performance of a coated Inconel steel substrate. A final proposed concept design, including a detailed description and analysis of potential candidate coating technology is expected at the completion of the Phase I effort. PHASE II: Using the data derived from Phase I, in Phase II the proposer shall fabricate and integrate a prototype of the technology into a nominal projectile form-factor. The proposer shall further their proof-of-concept design and determine the applicability of the coating for different surface materials. Upon evaluation of the design through a critical design review, the prototype hardware's survivability shall be demonstrated via high G testing (35,000 G objective) in an air launched munition and aerothermal ground testing. Information and data collected from these tests will be used to validate operational performance. PHASE III DUAL USE APPLICATIONS: Phase III selections shall identify large scale production alternatives and fabricate 20 prototypes that can be integrated into a nominal projectile form-factor to be identified by the SBIR: Army 20 Topics and Concepts Government. Live fire tests will be conducted, and the prototype integrated with projectile form-factor will have to withstand shock loads approaching 35,000g's. Phase III selections will develop of a cost model of expected large scale production to provide estimates of non-recurring and recurring unit production costs. Production concept for commercial application will be developed addressing commercial cost and quality targets. Phase III selections might have adequate support from an Army prime or industry transition partner identified during earlier phases of the program. The proposer shall work with this partner (TBD) to fully develop, integrate, and test the performance and survivability characteristics of the design for integration onto the vendor's target platform. REFERENCES: 1. Abdul-Aziz A. Durability Modeling Review of Thermal- and Environmental-Barrier-Coated Fiber-Reinforced Ceramic Matrix Composites Part I. Materials (Basel). 2018;11(7):1251 2. Eugenio Garcia,Reza Soltani,Thomas W. Coyle,Javad Mostaghimi,Angel De Pablos,Maria Isabel Osendi,Pilar Miranzo, Thermal Behaviour of Thermal Barrier Coatings and Steel/Thermal Barrier Coatings Structures, Advances in Ceramic Coatings and Ceramic Metal Systems: Ceramic Engineering and Science Proceedings, Volume 26, Ceramic Engineering and Science Proceedings, 2005 3. Padture N. P.; Gell M.; Jordan E. H. (2002). "Thermal Barrier Coatings for Gas-Turbine Engine Applications". Science. 296 (5566): 280 284. 4. Clarke, D.R.; Oechsner, M.; Padture, N.P. Thermal-barrier coatings for more efficient gas-turbine engines. MRS Bull. 2012, 37, 891 898 KEYWORDS: Thermal Protection System, Advanced Materials, Artillery, Conformal Coatings, Hypersonics, Extreme Environments