News 1998 Army Science and Technology Master Plan



15. Materials, Processes, and Structures

The Army’s 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 life–cycle 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 E–18 and the following paragraphs provide a summary of key capabilities and trends for each technology subarea.

Table E–18.  International Research Capabilities—Materials, Processes, and Structures

Technology

United Kingdom

France

Germany

Japan

Asia/Pacific Rim

FSU

Other Countries

Materials 2s.gif (968 bytes) Metal alloys; composites; polymers 2s.gif (968 bytes) Metal alloys; composites; ceramics 2s.gif (968 bytes) Metal alloys; composites; ceramics 1s.gif (931 bytes) Ceramics; composites; polymers; ferrous allows China

5s.gif (958 bytes) Refractory & rare–earth materials & alloys

4s.gif (949 bytes) Ti alloy Israel

5s.gif (958 bytes) Metal alloys; organic matrix composite

Processes 1s.gif (931 bytes) Welding & joining 2s.gif (968 bytes) C–C ceramic part fabrication 2s.gif (968 bytes) Functional gradient coatings 1s.gif (931 bytes) Polymer processing ROK

5s.gif (958 bytes) Tungsten processing

Australia

5s.gif (958 bytes) Composites

  Austria

5s.gif (958 bytes) Refracting metals

Structures 2s.gif (968 bytes) Lightweight engineering structures; smart structures 2s.gif (968 bytes) Energy– absorbing structures; smart structures 2s.gif (968 bytes) Engineering structures; smart structures 5s.gif (958 bytes) Structures; engineering structures   5s.gif (958 bytes) Ti; structures; welding; ion–beam coating  
Note: See Annex E, Section A.6 for explanation of key numerals.

 

a. Materials

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 included—metals, ceramics, polymers, composites, coatings, energetic, semiconductors, superconductors, and electromagnetically functional materials.

Technical challenges focus on extending the state–of–the–art knowledge of composition–microstructure–property relationships to allow modeling and prediction of material behavior involving very complex phenomena (e.g., ballistic penetration, long–term environmental exposure, chemical agent permeation). Specific areas of interest include:

Models to predict static and dynamic behavior of fiber/matrix interphases
Predictive models of environmental durability for monolithic and composite materials
Models for the interactions of gases, vapors, and liquids with polymeric barriers
Cost–efficient, lightweight transparent armors for personnel and sensor protection
Tungsten and other heavy metal alloys/microstructures that will provide equal ballistic performance as depleted uranium
Steels with high–strength, toughness, and ballistic properties that also are weldable and resistant to stress corrosion cracking
Modeling/mitigation of micromechanical failure mechanisms in elastomeric materials
Improved nonlinear and other optical materials for protection of soldier’s vision, direct view optics, and sensors.

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 carbon–carbon (C–C) 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 high–purity 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.

b. Processes

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 lay–up and curing, machining, and chemical vapor deposition. Coating processes are of special interest because they affect so many devices and components. Ion–beam–assisted 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, real–time online sensing (especially at very high temperatures) with adaptive control technology. Specific challenges include:

Knowledge–based models for thermal and thermomechanical processing
Improved joining and repair of polymers, ceramics, and organic and inorganic matrix composites
Development of process specific sensors and control systems
Techniques to achieve near or actual net shape components of complex geometry and variable composition in more affordable materials/design systems.

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 high–density tungsten carbide ceramics that has potential for armor technologies. Russian capabilities in welding and ion–beam coating may also be of interest. The Army Research Laboratory (ARL) recently initiated development of a new class of high–density 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 low–density materials suffer damage accumulation effects and reduced effectiveness as the impact threat increases, particularly against modern, high–density eroding rod penetrators. High–density ceramics inherently offer greater space effectiveness (2–3 times more efficient than steel). Current efforts are trying to optimize these high–density 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 near–term goal of the ASTMP is to increase the ballistic performance of tungsten to equal that of depleted uranium (as measured in depth of penetration). Korea’s 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 long–term requirements. In addition, worldwide interest is growing in the potential for bioprocessing to replace more costly or environmentally threatening chemical processes.

c. Structures

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 structures—instrumented 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 crash–survivable and energy–absorbing materials. Japan has a significant capability in structural design, and in practical engineering of crash–survivable vehicles and structures. Finally, Russia’s expertise in titanium alloys may be applicable to some Army structural needs.

AMC POC: Dr. Rodney Smith
Army Materiel Command
AMXIP–OB
5001 Eisenhower Blvd.
Alexandria, VA 22333–0001
e–mail: icpa@hqamc.army.mil

IPOC: Mr. Stephen Cohn
Army Research Laboratory
AMSTL–TT–IP
2800 Powder Mill Road
Adelphi, MD 20783–1197
e–mail: scohn@arl.army.mil

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