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Ceramic-Metal Joining for Hypersonic Vehicle and Missile Components
Navy SBIR 2016.1 - Topic N161-046 NAVSEA - Mr. Dean Putnam - dean.r.putnam@navy.mil Opens: January 11, 2016 - Closes: February 17, 2016 N161-046 TITLE: Ceramic-Metal Joining for Hypersonic Vehicle and Missile Components TECHNOLOGY AREA(S): Weapons ACQUISITION PROGRAM: ONR FNC SHD-FY15-07 (Hypervelocity Projectile) The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: Develop innovative techniques for joining ceramic components to metal airframe components that will withstand the aerothermal heating of high-speed air vehicles. DESCRIPTION: Development of high-speed munitions, such as the Hypervelocity Projectile (HVP), has many technical challenges due to the aerothermal heating and stresses that munition components are subjected to during flight. The HVP munition control surfaces expect to face very high aerothermal stresses which require a combination of materials to address these issues. The joining of these materials is vital to munition performance as its integrity during launch and lengthy flight times must be maintained. In addition to control surface applications, joining technologies will also be applicable to missile components (such as radomes) with performance parameters that will be extended (for example speed and time of flight) with future missile development programs. In a high-speed air vehicle environment, aerothermal heating subjects vehicle components to high temperatures that affect their structural integrity. Several of the components of a high-speed air vehicle are affected. Fins, for example, experience severe heating on the leading edges, but the temperature drops significantly a short distance back from the edge. The majority of the fin may experience temperatures that are more moderate. An attractive design approach would be to use higher temperature materials like ceramics on the leading edge and common aerospace materials such as titanium alloys for the bulk of the fin, since only the leading edge portion may exceed allowable temperatures for metals. This approach requires an attachment technology to affix ceramic leading edge inserts onto metal components such as fins. These inserts must be attached in a manner that will survive the temperatures and stresses resulting from flight. Ceramic missile radomes, which are sometimes mounted to the metal airframe with polymer adhesively bonded composite rings, begin to fail as vehicle flight speeds and times increase. The thermal capabilities of polymer adhesives are exceeded which then cause the joints to fail. The Navy needs a technology that adheres ceramic to metal and withstand the high temperatures and stresses incurred while a high velocity airframe component is in flight. This effort requires combined knowledge of hypersonic vehicle design, aerothermal heating concepts, mechanical engineering (modeling of stresses), and materials science including ceramics, metals, and joining. The successful approach will involve innovative design in addition to appropriate materials science concepts. The principle transition for this topic is control surfaces or fins on hypersonic vehicles such as advanced missiles or the rail gun projectile (Ref. 3). These control surfaces can be relatively small, with dimensions of just a few centimeters and a sharp leading edge radius of approximately 1 mm or less. The thickness of the control surface may only be a centimeter or less, as well. Since weight is always a concern for air vehicles, lower density and high temperature capability technologies are crucial. Flight speeds range from Mach 5 to 8, and flight times range from a few seconds to several minutes. Launch is typically at sea level. The missile body diameters may range from five inches to over one foot. With these conditions, the temperature of the leading edge is too high for metals to function properly (Ref. 1). Past efforts involving ceramic leading edges have concentrated on much larger structures on the scale of manned vehicles like the space shuttle, with significantly more blunt leading edges. In contrast, for high-speed air vehicle applications, oxide ceramics and silicon nitride are of primary interest, and would be attached to common aerospace metals such as titanium alloys. Many materials have been investigated, including ceramic matrix composites and carbon-carbon composites, but for these sharp edges, the most promising class of materials has been the Ultra High Temperature Ceramics (UHTCs). This group includes materials such as silicon carbide and zirconium diboride. Johnson (Ref. 2) discusses the advantages of these materials for leading edges. Technologies and processes are sought to allow successful attachment of appropriate ceramic leading edge inserts to high temperature metal structures such as the fins. The means of attachment may include mechanical designs, brazing, diffusion bonding, or combinations of these. The attachment design must mitigate or accommodate the stresses resulting from the temperature gradient and withstand mechanical loads as well. For example, a control surface on a missile launched at Mach 5 may experience temperatures as high as 2000°C at the leading edge, and 200°C at the root. This temperature differential will result in significant stresses, which will be combined with stresses from aerodynamic pressure as control surfaces articulate. A suite of tests provided by the company will be used to characterize the technology through the required service conditions including temperature, oxidation, and stresses. The technology developed in this topic will enable higher performance projectiles and missiles to operate at higher speeds and for longer flight times. There is also an element of cost reduction potential concerning materials costs in manufacturing. Fins composed entirely of ceramics can be very expensive. A solution using ceramic inserts with metal structures, for example, could reduce total munition acquisition cost. This would manifest itself even more in a projectile application (vs. missile), where higher quantities are envisioned for procurement. Development of high-speed munitions, such as the Hypervelocity Projectile (HVP), has many technical challenges due to the aerothermal heating and stresses munition components are subjected to during flight. The HVP is being developed for both the Navy MK 45 MOD 4 gun system and the Electromagnetic Rail Gun (EMRG) application. In both of these applications, munition control surfaces are expected to face very high aerothermal stresses, requiring a combination of materials to address these issues. The joining of these materials is vital to the munition performance as its integrity during launch and lengthy flight times that must be maintained. PHASE I: The small business will investigate feasibility of their concept for joining ceramic components to metal airframe components by conducting bench-scale experiments joining model materials of interest. The concept will be substantiated by using standard materials science investigative methods (optical and electron microscopy, x-ray diffraction, microhardness), and the thermostructural capabilities of the joints will be measured. Modeling should be employed to estimate thermal shock response and testing shall be used to validate modeling to prove feasibility. The Phase I Option, if awarded, would include the initial layout and capabilities description to build the unit in Phase II. PHASE II: Based on the results in Phase I and the Phase II Statement of Work (SOW), the company will scale-up the attachment methods to produce a notional model component full scale or sub-section prototype. Additionally, radome sub-sections may be prepared. The prototype components should be subjected to extensive characterization through testing and analyzing with the goal of demonstrating that the attachment method can function under the required service conditions including temperature, oxidation, and stresses. The suite of tests that demonstrate the characterization of the technology will be identified by the small business during this phase and must be approved by the EMRG program office. These tests may include high temperature mechanical tests, thermal shock tests, oxidation tests, non-destructive testing, and microstructural examinations. The company will prepare a plan to transition the technology to the Navy during Phase III for a specific application to be identified with Navy input during execution of Phase II. Information in this phase may possibly be classified depending on level of success and tie-in with program. PHASE III DUAL USE APPLICATIONS: The HVP is being developed for both the Navy MK 45 MOD 4 gun system and the Electromagnetic Rail Gun (EMRG) application. Transfer of this technology to Navy use will involve manufacture of components such as fins including the ceramic inserts able to meet performance parameters of the EMRG HVP. The contractor will support the manufacturing of the components employing the technology developed under this topic, and will assist in the qualification testing defined by the Navy program. This testing will be similar to that described in Phase II, but more extensive. It is likely that work in Phase III will be classified. There are many commercial uses for ceramic-metal joining, including medical components, vacuum feed troughs, cutting tools, and electronic components. The potential for application of the developed technology into these areas will depend on a comparison with existing technologies in use (typically brazing) including performance and cost. REFERENCES: 1. Kasen, Scott D. Thermal Management at Hypersonic Leading Edges. PhD Thesis, University of Virginia, 2013. 2. Johnson, Sylvia. "Ultra High Temperature Ceramics: Application, Issues and Prospects." 2nd Ceramic Leadership Summit Baltimore, MD August 3, 2011, American Ceramic Society. http://ceramics.org/wp-content/uploads/2011/08/applicatons-uhtc-johnson.pdf 3. Atherton, Kelsey. "The Navy Wants To Fire Its Ridiculously Strong Railgun From The Ocean." 8 April 2014. http://www.popsci.com/article/technology/navy-wants-fire-its-ridiculously-strong-railgun-ocean KEYWORDS: Ceramic-metal joining; hypersonic vehicle design; ultra-high temperature ceramics; control surfaces at hypervelocity; hypersonic vehicle fins; ceramic missile radomes TPOC-1: Curtis Martin Phone: 301-227-4501 Email: curtis.a.martin@navy.mil TPOC-2: Dave Cooke Phone: 540-653-2379 Email: dave.cooke@navy.mil Questions may also be submitted through DoD SBIR/STTR SITIS website.
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