5. Materials Science
Materials science research supports the entire Army materiel acquisition effort by ensuring that materials exist to fully satisfy future mission requirements for improved firepower, mobility, armaments, communications, personnel protection, and logistics support. Research priorities are defined in the Material Science Investment Strategy Plan, which is prepared by the Army Materials Coordinating Group. This Group is composed of scientists from ARO, participating RDECs, ARL Directorates, and TRADOC. This plan outlines a strong multidisciplinary program in materials science that emphasizes research in five broad areas:
(1) Manufacturing and processing of structural materials for Army vehicles and armaments
(2) Materials for armor and antiarmor
(3) Processing of functional (electronic, magnetic, and optical) materials
(4) Engineering of material surfaces
(5) Nondestructive characterization of components for in-service life assessment.
Related areas of materials research undertaken by other service and Government agencies will impact Army missions. To exploit advances in these areas, ARO actively leads the Tri-Service Materials Science Working Group under Project Reliance in planning and conducting basic research programs having a proper balance of service specificity and commonality. In certain areas of materials research, more than one service has a vested interest in supporting programs. These areas are leveraged to optimize the potential for creating scientific discoveries and breakthroughs. International leveraging is also emphasized by coordinating collaborative programs with ARO Far East Office and the European Research Office to provide a flow of new ideas and concepts in materials development.
b. Major Research Area
The materials field is highly interdisciplinary, encompassing such diverse specialities as physical metallurgy, solid-state physics, textile science, chemistry, biology and biotechnology, penetration mechanics, surface science, and materials analysis. Studies involving combinations of these disciplines are used to enhance our understanding of:
- Synthesis and processing of structural materials
- Deformation and fracture phenomena
- Defect engineering and processing
- Beam engineering and surface modification
- Plasticity and toughness of materials
- Nondestructive characterization
Synthesis and Processing of Structural Materials Research in the structural materials arena is driven by Army needs for lighter and higher performance systems. These materials are often engineered to deliver superior performance to meet specific design requirements. The underlying challenges in manufacturing such materials are developing improved understanding of the interrelationships between processing, microstructure and properties, and developing innovative approaches to synthesize new materials reliably and at lower cost.
Deformation and Fracture Phenomena This research focuses on developing an understanding of material behavior under static, cyclic, and dynamic loading conditions with emphasis on the response of advanced materials and composites to complex loading conditions that are imposed on high performance weapons systems.
Defect Engineering and Processing Research in this area involves investigations underlying thermodynamics and kinetic principles that control the evolution of defects in materials, identifying the limits that defects impose on the synthesis and processing of future materials, and developing insight and methodologies for the utilization and manipulation of defects to produce materials with new or enhanced properties.
Beam Engineering and Surface Modification Research in this area emphasizes surface engineering as this relates to materials modification, processing, and the reliability of Army systems in service. The goals are aimed at discovering atomic/molecular/macroscopic processes governing the deterioration and adhesion of materials.
Plasticity and Toughness of Materials The goals of this effort focus on investigating novel approaches for processing materials with greatly improved properties with an emphasis on identifying the fundamental aspects of chemistry and structure that influence toughness and mechanical behavior under various time dependent stress and temperature conditions.
Nondestructive Characterization Nondestructive characterization of materials and processes relate to investigating the concepts, techniques, and sensors for detecting and characterizing defects, contaminants, constituents, and microstructure that affect the performance and reliability of advanced materials, particularly where there is no existing nondestructive capability.
Overall, the approach to new materials development considers three levels of scaling. On the submicroscopic level, research is concerned with the manipulation of atoms and molecules and of the interactive forces which bind them. There is a strong emphasis on such topics as electronic and atomic structure, lattice vibrations, and the many interactions of radiation and particles with condensed matter. At the microscopic level, the field is concerned with the effects of chemistry, microstructure level, and phase transitions on the structural and functional properties of materials. At the macroscopic level, research is concerned with the continuum behavior of materials and composites. There are expanding opportunities for advancing the science of materials through continued integration and understanding of the interrelationships between the microscopic and macroscopic domains. This is reflected by the increasing integration of materials modeling and numerical simulation into materials science.
c. Other Research Areas
Much of the research is involved with laying the foundations for the development of future generations of materials and material processing technologies. These other research areas include:
- Welding and joining
- Nanocomposites and biomimetic materials
- High toughness low density nonequilibrium materials
- Biosynthetic fibers
- Novel materials for thermoelectrics
A major interest for the Army is to introduce new approaches to small batch manufacturing, which can provide new levels of reliability at reduced costs. Flexible manufacturing approaches, like the composite lay up approach shown in Figure V11, are under development. The goals of these programs are to streamline and automate the manufacturing processes that lead from the initial computer-aided design to final component production.
Figure V-11. The development of flexible manufacturing techniques promises to improve on the reliability and lower the cost of future Army materiel acquisitions.
d. Benefits of Research
New generations of materials with vastly improved properties are also under development. Technology has now progressed to the point where it is possible to observe and engineer materials at the atomic scale. This opens the possibility of introducing much greater robustness into the design and performance of materials. For example, a new class of smart materials that is under development will be able to sense its environment and significantly alter its properties to adapt to changing conditions. Likewise, molecular recognition and self-assemble techniques, which mimic natural processes, are being investigated as a synthesis route to new classes of multifunctional supramolecular systems. This research is setting the stage for new generations of materials that will bear scant resemblance to the rudimentary materials technology that the Army depends on today. As noted in Figure V-23 at the end of this chapter, materials science supports practically all of the Technology Areas detailed in Chapter IV.