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This Defense Intelligence Reference Document, DIA-08-0912-008, is dated 12 January 2010. It was prepared by the Defense Warning Office's Acquisition Support Division at the Defense Intelligence Agency as one of a series of FY 2009 technology reports under the Advanced Aerospace Weapon System Applications program. It reviews materials for launch vehicles, space vehicles and reusable rocket engines, including aluminum alloys, polymer and metal matrix composites, titanium and nickel alloys, and titanium aluminides. It concludes that newer materials and integrated design could improve on the space shuttle.
From the source: Release of 2026-09-18 Incident: 1/12/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys the structural materials needed for advanced aerospace platforms and argues that material choice cannot be separated from overall vehicle design, because launch vehicles, space vehicles, reusable systems, and propulsion hardware each face different temperature, durability, weight, and manufacturing constraints. The report reviews a range of candidate material classes, including advanced aluminum alloys; polymer-, aluminum-, and titanium-matrix composites; titanium alloys; nickel-base alloys; refractory metals; ceramic-matrix composites; carbon-carbon composites; and titanium aluminides. It emphasizes that balancing performance against practical limits such as fabrication methods, cost, inspection, contamination control, and service environment remains a major challenge. Its overall conclusion is that many promising materials exist, but their usefulness depends on application-specific tradeoffs and on closer integration of material selection with design and manufacturing, with some systems judged to be more valuable targets for development than others.
UNCLASSIFIED/ /FOil OFFl@IAL YSli 8Ptllf • Once a case is present, can the structure be repaired (for example, by fusion or friction stir welding)? The Air Force Materials and Manufacturing Directorate is starting a new project intended to address these questions. The motivation for this program is hypersonic flight vehicles. The results from th is U.S. Air Force program should prove highly useful to the design of future reusable SSO vehicles. Earlier uses of Ti alloys at high temperatures included the skin and much of the load bearing structure of the SR-71 Blackbird. This airplane flew successfully at peak speeds in excess of mach 3.2 for 34 years (1964-1998). While the maximum skin temperatures are not readily available, they were in excess of 300 °Celsius. There were no known issues involving a case during the SR-71's service. Notably, the primary alloy used for the SR-71 was one of the original ~-Ti alloys, B-120 VCA, the composition of which is Ti-13V-11Cr-3AI. The primary reason for choosing this alloy was that it is much easier than any of the a +~ Ti alloys are to roll into sheet gauges. Today there are newer ~- Ti sheet alloys featuring a better balance of properties that could be used in the same way as B-120 VCA. The most common of these is Ti-15V-3Cr-3Sn-3AI. However, the successful use of B- 120 VCA raises the question of whether ~- Ti alloys are more resistant than a+ ~ alloys such as Ti-6-4 are to a case formation. The attraction to using Ti alloys, in addition to their structural efficiency, is the extensive industrial base for making the material in a variety of product forms and the extensive knowledge base resulting from the many successful applications of Ti alloys in high-performance products. For example, the ability to superplastically form Ti alloys such as Ti-6-4 creates the opportunity for design of a structure that functions both as load bearing and as thermal protection. Ti Matrix Composites As Table 1 showed, Ti alloys are not especially attractive for their specific stiffness. One way to overcome this limitation is to reinforce a Ti alloy matrix with SiC fibers. In this case, the fibers are "long" fibers-they have sufficient length for the matrix to transfer the maximum possible fraction of the external load to the fiber. The fibers are essentially monofilaments and must be carefully placed so adjacent fibers do not touch one another. Areas of contact between fibers essentially are incipient cracks that degrade the mechanical strength. As Table 2 shows, TMCs have excellent properties. Table 2. Example of Properties of Ti Matrix Composites Property Property Value (English /Metric Units) Ultimate tensile strenqth 276 ksi / 1902 MPa Young's modulus 32.8 msi / 226 GPa Strain to fracture 0.95% Density 0.16 lb/in 3 / 4.43 q/cm 3 Fiber Volume fraction 0.39 14 UNCLASSIFIED/;SFOR. OFFl&IAL Y&li 8Ptllf
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 27 pages are in the text index: search them above, or from the library's search.