15. Materials, Processes, and Structures
The Armys materials, processes, and structures program provides enabling technologies that are used to construct every physical system or device used by the Army. This program provides unique solutions and options that increase the level of performance and durability, and reduce the maintenance burden and lifecycle costs of all Army systems.
Advances in basic materials, materials processing, and structures are integral objectives of a number of opportunities discussed throughout the ASTMP and this annex, including materials for aeropropulsion, characterization of structures for rotorcraft, ballistic protection for soldier systems, materials and structures for hypervelocity missiles; and structures for ground vehicles. Table E18 and the following paragraphs provide a summary of key capabilities and trends for each technology subarea.
Table E18. International Research CapabilitiesMaterials, Processes, and Structures
|Materials||Metal alloys; composites; polymers||Metal alloys; composites; ceramics||Metal alloys; composites; ceramics||Ceramics; composites; polymers; ferrous allows||China
Refractory & rareearth materials & alloys
Metal alloys; organic matrix composite
|Processes||Welding & joining||CC ceramic part fabrication||Functional gradient coatings||Polymer processing||ROK
|Structures||Lightweight engineering structures; smart structures||Energy absorbing structures; smart structures||Engineering structures; smart structures||Structures; engineering structures||Ti; structures; welding; ionbeam coating|
|Note: See Annex E, Section A.6 for explanation of key numerals.|
The materials subarea focuses on materials with superior properties required for use in structural, optical, armor and antiarmor, CB and laser protection, biomedical, and Army infrastructure applications. All classes of materials are includedmetals, ceramics, polymers, composites, coatings, energetic, semiconductors, superconductors, and electromagnetically functional materials.
Technical challenges focus on extending the stateoftheart knowledge of compositionmicrostructureproperty relationships to allow modeling and prediction of material behavior involving very complex phenomena (e.g., ballistic penetration, longterm environmental exposure, chemical agent permeation). Specific areas of interest include:
Models to predict static and dynamic behavior of fiber/matrix interphases
As the table illustrates, a number of countries have strong capabilities in advanced materials. The U.K., France, and Germany all have expertise in metal alloys and composite materials. Noteworthy here is the special capabilities that France is developing in carboncarbon (CC) and other ceramics and in the design of crash survivable structures as noted elsewhere in this annex. Japan is a world leader in "fine ceramics." Fine ceramics refers to highpurity ceramics with specific performance characteristics, as opposed to bulk ceramics as might be employed for ballistic protection. Russia has strong capabilities in bulk ceramics as well as in titanium and steel alloys. In addition, Israel has niche capabilities in metal alloys and in organic matrix composites.
Materials processing includes all technologies by which raw or precursor materials are transformed into useful materials or components with the requisite properties and at an acceptable cost for Army applications. This includes such technologies as casting, rolling, forging, sintering, polymerization, composite layup and curing, machining, and chemical vapor deposition. Coating processes are of special interest because they affect so many devices and components. Ionbeamassisted deposition and pulsed laser deposition are two areas of keen interest. Improved process control techniques are also sought, especially related to resin transfer molded composites and Smartweave armor materials.
A major technical challenge involves integrating noncontact, realtime online sensing (especially at very high temperatures) with adaptive control technology. Specific challenges include:
Knowledgebased models for thermal and thermomechanical processing
Several foreign capabilities are of interest in the materials processing subarea. The United Kingdom has strengths in welding and joining. Germany has unique capabilities in explosively formed projectile (EFP) and other warhead metallurgy and processes for deposition of functionally gradient materials. Japan has been and is expected to continue to be a major developer and producer of fibers and matrix feedstock for advanced polymer composites that are essential for many advanced materials. Austria has also been identified as having tungsten processing research of interest and Australia as having research in composites.
France has special skills in highdensity tungsten carbide ceramics that has potential for armor technologies. Russian capabilities in welding and ionbeam coating may also be of interest. The Army Research Laboratory (ARL) recently initiated development of a new class of highdensity ceramics (defined as any ceramic whose density is greater than steel (7.85 gm/cc). While conventional ballistic ceramics offer excellent protection against conventional small arms threats, these lowdensity materials suffer damage accumulation effects and reduced effectiveness as the impact threat increases, particularly against modern, highdensity eroding rod penetrators. Highdensity ceramics inherently offer greater space effectiveness (23 times more efficient than steel). Current efforts are trying to optimize these highdensity ceramics for ballistic application.
Korea has a noteworthy program in tungsten penetrator technology that could be beneficial to the U.S. Advanced materials technology offers enhanced ballistics, increased range, and lethality for penetrators. Specific heat treatment processes for tungsten alloys have been developed by South Korea that offer the potential to enhance impact strength for penetrators. A nearterm goal of the ASTMP is to increase the ballistic performance of tungsten to equal that of depleted uranium (as measured in depth of penetration). Koreas heat treatment process could increase the impact strength of tungsten to meet ASTMP milestones.
Finally, readers should refer to the discussion of biological sciences that addresses the rapidly growing field of bioprocessing, where researchers are looking to biomimetic materials (such as spider silk) to meet critical longterm requirements. In addition, worldwide interest is growing in the potential for bioprocessing to replace more costly or environmentally threatening chemical processes.
This subarea focuses on developing structural elements with a high level of structural integrity that are inspectable, analyzable, and can survive the harsh combat environment. To be cost effective the design must integrate advanced structural concepts that are compatible with mass production manufacturing technologies. The structures must also be designed to specific vibration and noise levels to maintain crew comfort and a low noise signature. Particular emphasis is on design tools, modeling, failure and fatigue, and life prediction analysis. In addition, developing nondestructive evaluation (NDE) techniques for identification and quantification of defects and anomalies in composite structures is very important.
A growing area of worldwide research interest is smart structuresinstrumented structural designs that adapt to external conditions and stimuli to optimize performance. Closely related to this is the use of embedded sensors (usually based on fiber optics) for monitoring performance and structural conditions. The U.K., France, and Germany all have significant capabilities in this area and offer potential opportunities for cooperation.
The U.K. and Germany develop and market military systems for lightweight bridging and other civil engineering applications, and have sound capabilities in alloys and structural design for such systems. As mentioned earlier, France has special expertise in developing crashsurvivable and energyabsorbing materials. Japan has a significant capability in structural design, and in practical engineering of crashsurvivable vehicles and structures. Finally, Russias expertise in titanium alloys may be applicable to some Army structural needs.
AMC POC: Dr. Rodney Smith
Army Materiel Command
5001 Eisenhower Blvd.
Alexandria, VA 223330001
IPOC: Mr. Stephen Cohn
Army Research Laboratory
2800 Powder Mill Road
Adelphi, MD 207831197
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