OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Hypersonics; Space Technology; Advanced Materials 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 the Announcement. 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: This topic seeks to develop advanced materials and assemblies of non-eroding, shape-stable next-generation reentry from space vehicle nosetips that will enter the atmosphere at ~ Mach 20. The nosetips must be stable in all weather conditions and not rely on an ablator material to control the heat load. DESCRIPTION: The Department of the Air Force is seeking advanced materials and assemblies for next-generation reentry vehicle nosecones and/or nosetips that can operate in all weather conditions and are non-eroding and shape-stable. This topic seeks to identify next generation materials that are not prime reliant on a coating and can go beyond the performance limits of coated carbon/carbon composites by the incorporation of more durable materials throughout the nosetip structure. While coated carbon/carbon composites may be an important sub-element of an all-weather assembly, the focus should be on new advanced materials that will exceed the performance, operational duration, and environmental limitations of coated carbon/carbon composites. If cooling is required, it should not be done through ablation but accomplished by other mechanisms. PHASE I: As this is a Direct-to-Phase-II (D2P2) topic, no Phase I awards will be made as a result of this topic. To qualify for this D2P2 topic, the Government expects the applicant(s) to demonstrate feasibility by means of a prior Phase I-type effort that does not constitute work undertaken as part of a prior SBIR/STTR funding agreement. Applicant(s) may have already identified compositions of interest through previous efforts or may identify compositions through this work based on prior observations. Materials of interest include ultra-high temperature ceramic composites, co-continuous ceramics and ceramets, and refractory metal or platinum-group alloys and their carbides or nitrides. Thermal-mechanical-physical and environmental property evaluation test results from Phase I-like efforts should be included. The applicant(s) must have validated the product-market fit between the proposed solution and a potential Air Force stakeholder. The applicant(s) should have defined a clear, immediately actionable plan with the proposed solution and the Air Force customer. The feasibility study should: (1) identify key potential AF end user(s) for the non-Defense commercial offering that solves the AF need, (2) describe integration cost and feasibility with current mission-specific products, and (3) describe how the technology can be used by other DoD or government customers. PHASE II: Awardee(s) should identify, produce, and qualify candidate materials with thermal-mechanical -physical and environmental property evaluations, along with stress-strain modeling, component geometry optimization, and arc jet testing. Innovative processing techniques, such as field assisted sintering (FAST), additive manufacturing (AM), electro-forming (E-form), polymer infiltration and pyrolysis (PIP), or chemical vapor deposition (CVD) as well as other infiltration methods for composites may be of interest. Shape stability under nosetip surface temperatures ranging from 5000-8000 degrees Fahrenheit should be considered as well as shock-loading relevant to weather conditions consistent with a chosen ballistic trajectory through the atmosphere. Transpiration cooling to achieve shape-stability in these environments is permissible but the offeror must show prior proof of robustness in relevant ground testing. Identification of manufacturing or production issues and business model modifications required to further improve the product or process with relevance to improved sustainment costs, availability, or safety, should be put forward and documented. Air Force sustainment stakeholder engagement is paramount to successful validation of the technical approach. These Phase II awards are intended to provide a path to commercialization, not the final step for the proposed solution. A planned design iteration in conjunction with a plan for testing and a scale-up approach for a beyond-phase-II effort should be proposed. It is anticipated that this program will require a team approach with several disciplines: [1] material modelers that can use advanced methods to assess candidate materials that will have the thermal, physical, mechanical, dynamic, and environmental properties needed to survive the extreme conditions endured by candidate nosetips, [2] process and performance modelers to build property and life models using different materials with various architectures to provide uniform distribution of pressure and temperature under potential use conditions, and [3] fabricators to produce the identified materials with various configurations. The program is also required to: [4] screen test selected materials or structures fabricated into articles at either a University, Private, or Government test facility, and [5] conduct the final test demonstration test as an arc jet test at a government facility. The shape and size of the nosetips for these tests will be determined in coordination with the government program manager, test facility, and offeror. Finally, the program requires that: [6] the offeror conduct microstructural characterization of the nosetips both pre- and post-testing. The performance and microstructural data shall be used to validate and inform developed models. Test articles should be delivered to the Air Force during the program and upon completion of the Phase II effort. PHASE III DUAL USE APPLICATIONS: The awardee(s) can expect to pursue commercialization of the shape-stable high temperature compatible materials found during Phase II. The technologies may be transitioned by expanding mission capabilities to a broad range of potential government and civilian users. Direct access with end users and government customers will be provided with opportunities to receive Phase III awards for providing the Government with additional research, development, and diagnostic/performance testing on materials meeting the requirements of Phase II. Additionally, direct procurement of shape-stable refractory materials in specific shapes and sizes of nosetips determined in coordination with the government program manager may be part of the Phase III effort. REFERENCES: 1. Savino, R., Criscuolo, L., Di Martino, G. D., Mungiguerra, S. Aero-thermo-chemical characterization of ultra-high temperature ceramics for aerospace applications J. Euro. Ceram. Soc. 2018, 38, 2937-2953.; 2. Savino, R., Mungiguerra, S., Di Martino, G. D. Testing ultra-high-temperature ceramics for thermal protection and rocket applications Adv. Appl. Ceram. 2018, 117, S9-S18.; 3. H. Minnich, J. Brunner, "Thermostructural Assesment of Erosion Resistant Nosetip Constructions", AFWAL-TR-84-4191, 1985.; 4. J. Brown, "Erosion Performance of Carbon-Carbon Composite Materials", 1980.; 5. M. Sherman, "Hardened Reentry Vehicle Development Program - Erosion Resistant Nosetip Development", DNA 001-74-C-0033, 1975.; 6. R. Diriing, D. Eitman, "Development of Highly Erosion Resistant Nosetip Materials, SAI-061-81-09-08/N60921-80-C-0068, 1981.; 7. M. Abbett, et. al, Passive Nosetip Technology Program, SAMSO-TR-74-96, 1975.; KEYWORDS: refractory materials; ceramic or cermet composites, shape-stable ultra-high temperature materials; reentry nosetips; all weather conditions
