SBIR-STTR Award

Hypersonic air platform component functionality and survivability in the extreme thermal and mechanical load environments of Mach 5+ flight require oxidation-resistant materials capable of retaining mechanical strength, toughness, and structural integrity at high temperatures. Realizing morphing capability in multi-mission air platform aerodynamic control surface components adds a requirement of seamless flexibility and another dimension of complexity and severity to the hypersonic material system requirements. The proposed development will utilize Ultramet’s decades of experience in the processing and application of advanced refractory materials to develop the component technology needed to impart a robust flexible, oxidation-resistant, and seamless morphing capability to aerodynamic control surfaces of hypersonic air platforms. In this project, Ultramet will demonstrate the feasibility of using advanced, flexible refractory materials to enable innovative component designs to impart morphing capabilities to aerodynamic control surfaces of hypersonic air platforms operating above 3000°F. A nominally 1" thick test component will be designed, fabricated, and subjected to high temperature oxidation testing and bend demonstration around a 12" radius. The deformable sandwich structure will be composed of a thin, ductile niobium outer facesheet, coated with a high temperature oxidation-resistant platinum-iridium coating, which will be bonded to a structural and deformable open-cell niobium foam core that is filled with highly insulating carbon aerogel. A layer of ceramic felt insulation and a niobium foam backing sheet will complete the structure. In Phase I, initial feasibility demonstration of the deformable high temperature control surface will include preliminary thermostructural modeling, prototype fabrication, and flexural and oxidation testing. Following successful demonstration, a specific hypersonic platform component will be identified in conjunction with an MDA prime contractor for continued materials and processing optimization in Phase II. Approved for Public Release | 20-MDA-10643 (3 Dec 2

Development of surface morphing technology is critical to enhance performance of multi-mission air platform aerodynamic control surface components operating under high-Mach conditions. In Phase I, Ultramet demonstrated the initial feasibility of a robust flexible, oxidation-resistant, and highly insulating multilayered structure for deformable aerodynamic control surfaces. In conjunction with design and modeling performed by Plus Designs Inc., the feasibility of a nominally 1" thick multilayered panel composed of thin refractory metal front side and back side facesheets, highly porous refractory metal structural open-cell foam, and ceramic felt insulation was demonstrated. Based on thermostructural modeling, front side (hot face) facesheet materials were selected that have good potential to operate at 3000°F and remain elastic. The flexible, high temperature open-cell foam near the hot face serves as a thermal/chemical standoff between the front side facesheet and oxide felt insulation to prevent unwanted reaction and reduce heat transfer to the felt. Near the back side (cool face), the foam provides additional structural support and interface contact resistance to reduce heat transport. During oxyacetylene torch testing to 3000°F, heat transfer through the multilayered structure yielded a back face temperature that was close to the 300°F target, and a means of further reducing temperature below the target was established through modeling of different insulator material combinations. Room temperature flexural tests to a 12" radius of curvature showed the ability of the multilayered structure to deform elastically, and thermostructural modeling indicated good potential for the structure to behave similarly at 3000"F. Maintaining high temperature oxidation resistance for a morphing surface is a significant challenge, as conventional ceramic protective coatings are brittle. The feasibility of thin, high-ductility platinum group metal coatings diffusion-bonded to the front side facesheet materials was demonstrated through oxyacetylene torch testing up to 3000°F to show oxidation resistance, and through post-test cyclic room temperature flexural testing to show retention of coating/facesheet flexibility and damage resistance. In Phase II, Ultramet will team with Northrop Grumman Defense Systems, a potential end user of the technology, and Plus Designs to target a specific MDA program application for the surface morphing technology and demonstrate performance through panel screening tests at the Air Force LHMEL facility to compare performance with competitive designs and through increased-scale panel tests at the Air Force Aerospace Structures Test Complex, which will include cyclic panel bending during high temperature testing. The deformable surface technology is anticipated to find application in non-airbreathing as well as airbreathing vehicles, and the proposed Phase II development and testing will be beneficial for both. Approved for Public Release | 22-MDA-11102 (22 Mar