Lightweight Armor Solution for the Expeditionary Fighting Vehicle

Materials Research & Design, Inc (MR & D) is pleased to submit this Phase I SBIR proposal for the design, fabrication, and ballistic testing of a lightweight armor system for use on the Marine Corps Expeditionary Fighting Vehicle (EFV). The proposed armor employs thin, lightweight modular metallic-clad ceramic tiles supported by a lightweight 3D woven composite. The metallic-clad ceramic serves to defeat the incoming projectile and the 3D woven composite acts as a momentum trap to capture the debris from the ceramic and projectile. The modular construction, in which the tiles are inserted in pockets formed in a 3D weave, allows for both 1) armor tailored to the threat, and 2) rapid, inexpensive repair. The SBIR will focus on lightweight B4C and SiC ceramic tiles clad in a ductile metal, e.g. Ti alloys, etc. The proposed design concept offers many advantages. The encapsulation process creates compressive residual stresses in the ceramic tile due to the thermal expansion mismatch between the tile and cladding. This compressive stress inhibits the fracturing process enabling the strike face material to remain coherent for longer times and at higher stresses to extend the damage imposed on the projectile. This improves the effectiveness of the ceramic tile which decreases the thickness needed to defeat a defined threat level. Furthermore, because the ceramic remains intact, the multi-hit capability of the system is improved. The metallic skin also protects against handling damage thereby increasing durability. The fabric pockets can be opened for localized armor replacement decreasing repair time and effort. The metallic jacket, ceramic tile and woven pockets are all corrosive resistant and structurally unaffected by high temperatures; therefore no degradation in ballistic performance can be expected. In order to optimize this design, it is necessary to specify several variables such as ceramic material and size of tile, metallic cladding and thickness, composite fibers and matrix, and details of 3D fiber architecture including warp weaver, warp stuffer, and fill yarn distributions. Rather than define these variables with a"cut and try"approach MR & D proposes to employ a dynamic structural model to audition design concepts and select those that are theoretically promising. Based upon the modeling results, MR & D will fabricate and supply armor for ballistic tests. Metallic-clad ceramic tiles will be purchased from Exothermics, Inc. 3D woven composite panels will be purchased from Albany Engineered Composites. Armor samples will be tested for ballistic performance at H.P. White Laboratories. The results of the tests will determine the feasibility of the proposed armor design.