2015-2016 Assessment of the Army Research Laboratory (2017) / Chapter Skim
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2 Materials Research
2 Materials Research
Pages 19-59
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From page 19... ...
The Army's mission is fundamentally intertwined with its ability to produce new and improved materials with a combination of properties that are more often than not unique to the requirements of the warfighter. As such, materials science is one of ARL's core technical competencies, with the Materials Research Campaign spread throughout the ARL enterprise.
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From page 20... ...
, more specific performance criteria or target product profiles will be needed for further development of some of these areas. Biohybrid Materials for Sensing Bio-nano-hybrid systems are being investigated for their potential applications for in vivo physiological monitoring, nanomedicine, traumatic brain injury (TBI)
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From page 21... ...
While inspired by natural polymers that derive their mechanical properties from hydrogen bonding, this project focuses on the use of reversible metal bonds as high-temperature tougheners. The emphasis in both projects on developing a mechanistic understanding is a strength, because so much of the other work on these topics is empirical.
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From page 22... ...
ENERGY AND POWER MATERIALS Accomplishments and Advances The quality of the research projects, the staff, and the facilities is comparable to high-quality research laboratories elsewhere in industrial and academic environments. Where there are gaps in the technical skills or methods needed for a project, the ARL staff demonstrate mature experience and judgment in seeking out high-quality collaboration with other non-ARL researchers within and beyond the Army research enterprise.
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From page 23... ...
Productive work may come from the team's interactions with that initiative focused on electrolytes, possibly including the effect of additives on interfacial reactivity. Advanced Energy Storage: Structural Batteries Using Additive Manufacturing The researchers are successfully developing techniques for fabricating multifunctional battery aterials using additive manufacturing (AM)
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From page 24... ...
Alkaline Fuel Cells: Optimizing Structure and Chemistry of Ion-Containing Polymers for Charge Transport This project focuses on the development of alkaline fuel cells. Conventional approaches rely on a liquid KOH electrolyte as a means of OH− exchange.
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From page 25... ...
The principal investigator has performed careful in situ measurements of this effect using an atomic force microscopy technique. The implementation of these experimental techniques is the main achievement of the work so far.
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From page 26... ...
To test the concept, an isotope power source was fabricated that generated 100 µW. The innovative concept applies to the investigation of three-dimensional (3D)
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From page 27... ...
LiCoPO4 has a high potential but usually exhibits significant capacity fade upon cycling. The ARL team found that mixing some Fe with the Co results in much less capacity fade, with minimal loss of overall capacity.
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From page 28... ...
Previous work showed that this solid-state electrolyte material had good conductivity. The idea is to change grain boundary (GB)
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From page 29... ...
The presentation on structural batteries using additive manufacturing has significant potential associated with its innovative approach. The project combines novel fabrication methods with insight into selection of compatible multifunctional elements that combine structural components with energy torage s components.
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From page 30... ...
The portfolio of the engineered photonics materials group shows a good balance of high-risk, longerterm work with nearer-term customer-driven solutions or incremental, critical technology refinement. This well-balanced portfolio is supported by a strong materials capability in staff expertise and laboratory or clean room infrastructure.
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From page 31... ...
This is one of the projects indicative of ARL's investments in more comprehensive modeling to support its strong core materials capabilities and competencies. This a very challenging problem, and the principal investigator is making good progress in describing radiative lifetime, including many-body effects such as phase-phase filling, screening, and quasiparticle renormalization.
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From page 32... ...
Short-Wavelength Infrared Device Modeling and Optimization This project is directed at the development of a comprehensive model that combines the finitedifference, time-domain electromagnetics of nanostructured surfaces with finite-element modeling, drift-diffusion transport to understand and optimize device designs and material structures. The model is comprehensive in that it included material, electronic, optical, and especially nanostructured geometric properties that strongly impact the electromagnetics.
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From page 33... ...
Photoacoustic Spectroscopy for Hazard Detection This project involves work on an elegant and simple device approach for detecting trace elements. While many optical detection techniques are available, these are usually large and contain many precision optical elements.
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From page 34... ...
The important software tool set coming from this research is not only essential for designers, but it may also provide critically sensitive parameters that could be used in process control for commercial partners and suppliers of imaging solutions to the Army, which necessitates engaging with the manufacturers. The project's principal investigator has started this engagement.
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From page 35... ...
The commitment by ARL to take advantage of the dynamic sector facilities at the Advanced Photon Source is noteworthy. In situ measurements performed using these facilities will provide the needed fundamental knowledge for developing and validating computational models for improved understanding of highstrain-rate effects.
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From page 36... ...
This project, which is also leveraging an Army Research Office-funded multidisciplinary university research initiative program on 2D polymer synthesis, is an example of successfully using computational tools to design and develop new materials. Grain Boundary Modeling and Simulation for Lightweight Protective Materials This program included a fundamental study on B4C that addressed the important issues at the root of its poor ballistic performance.
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From page 37... ...
The discussion of setting up a fiber and film facility, with future plans of adding additional diagnostics such as dynamic X-ray system is indeed exciting and fascinating. Grain Boundaries and Interfaces This project addresses the inelastic deformation due to contact loading of B4C.
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From page 38... ...
Exploiting Oxide Dispersion Strengthening in Ferritic Alloys for Lethality Applications This project is using the scale-up capabilities available at ARL for high-energy ball milling of owders and equal channel angular pressing processing to synthesize and fabricate oxide-dispersion p strengthened ferritic alloys. The bulk material fabricated with a microstructure consisting of nano- to microscale grains with larger-sized intermetallic precipitates and zirconium oxide dispersed particles, demonstrates substantially high room-temperature compressive strengths of the order of 1.2 GPa for those consolidated at 700°C, and 2.4 GPa for those at 1000°C.
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From page 39... ...
The film laminates do not need a separate matrix material like epoxy. However, their mechanical properties are sensitive to processing conditions, especially temperature.
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From page 40... ...
Large numbers of specimens can be produced for quasi-static and dynamic testing. High-Strain-Rate Deformation Mechanisms of Polymers This project uses new capability to characterize polymers such as polycarbonate and polymethyl methacrylate over a broad range of strain rates as accessed by the mini Hopkinson bar.
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From page 41... ...
The stated goal of connecting quantum mechanics, MD, dissipative particle dynamics (DPD) , and continuum models will require the ARL team to investigate multiscale strategies and go beyond the scale-coupling focus and software aspects of multiscale computational modeling.
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From page 42... ...
Grain-Boundary Modeling and Simulation for Lightweight Protective Materials The researchers work collaboratively with experimentalists in an effort to verify their calculations and thereby generate a better understanding of the effects observed in B4C and other ceramics. 3 LS-DYNA is a finite element code and MAT162 is a material model for use in LS-DYNA that may be used to simulate the onset and progression of damage.
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From page 43... ...
Atomistic and Mesoscale Modeling of Grain Boundaries This project involves DFT and MD work aimed at explaining how grain boundaries can be engineered to increase the toughness of B4C. The role of intergranular films is still not being evaluated, but it is a goal.
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From page 44... ...
An example of one such effort is a program directed toward grain boundary modeling of ceramics for light-weight protective materials. A suite of tools is being developed to permit simulation of grain boundary structure and properties under high-rate loading conditions.
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From page 45... ...
This can inform experimental efforts to manipulate interfacial properties to optimize lightweight protective armor materials. A suite of tools is being developed to permit simulation of grain boundary structure and properties under high-rate loading conditions.
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From page 46... ...
These samples are being examined for microstructure and unique microstructures have been identified. Grain/Interface Boundaries in Boron Carbide Due to Contact Loading This project addresses the formation of regions in B4C that are interpreted as amorphous bands.
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From page 47... ...
High-Performance Powder Metallurgy Titanium This project has the objective of producing low-cost (estimate $1 to $5 per pound for unalloyed powder) powder that can be consolidated into various Army applications by additive manufacturing or metal-injection molding processes with properties equivalent to those of wrought titanium.
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From page 48... ...
This project leverages work from the advanced experimental techniques project and greatly reduces the laser setup time for sample preparation from days to hours. While miniaturization of the split Hopkinson pressure bar test for very high strainrate testing is not new, the testing of strain rates up to 106 s-1 is novel.
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From page 49... ...
The approach to achieve ROMP-fiber interfaces suitable for high-strain-rate deformation on the experimental side is based on film and coupling agent chemistry experiments. Modeling efforts involve mostly MD simulations that are used to determine constitutive models for the interface that are then used for finite element method (FEM)
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From page 50... ...
The program will continue to develop the foundational science of grain boundary solute engineering in nano-duplex structures, devise engineering methods to control deformation at the nanoscale, advance processing techniques capable of producing suitable bulk material, and pursue the design and development of components that utilize these nanostructured materials. It needs to be noted that related work for producing bulk nanocrystalline material is ongoing in Australia, the European Union, Russia, and China.
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From page 51... ...
Numerous potential applications have been identified, including structural radomes and structural capacitors, but much more work is needed before these applications are realized. The project is not yet at the point of incorporating materials properties and processing into the topology optimization algorithms, and including microstructural sensitive properties in the algorithms is a major unrealized opportunity.
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From page 52... ...
ARL appears to be breaking new ground in this area and needs to ensure that the other DOD laboratories are aware of this basic technology. Creating a Soft and Stretchable Power System This project addresses the trade-off between performance and stretchability in power conversion.
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From page 53... ...
The project is well supported in the materials and devices area but might be aided by adding a staff member with a strong background in the areas of high-power inverters, drives, and hybrid vehicles. Improved Voltage Control and Stability of SiC Power MOSFETs This project is a noteworthy example of ARL work maturing into materials processing and devices that can strongly impact Army needs.
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From page 54... ...
Using a novel metamaterials approach in a highly sophisticated layered medium, the international team was able to realize reductions in the required stand-off from a vehicle surface by 85 percent relative to commercial solutions, while also improving the signal-to-noise ratio. Development proceeded from recognition of opportunity of novel materials, to initial evaluation, to refinement, to prototype antenna for vehicle (2″ height versus 14″ height, higher bandwidth, lower losses, etc.)
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From page 55... ...
Opportunities and Challenges Vertical 2D-3D Semiconductor Heterostructures There is a significant effort in modeling in this program -- which is absolutely critical, although the impact is less clear -- because the efficacy of efforts to model vertical transport at van der Waals interfaces using the various available codes, especially in the context of doped materials, has not yet been well developed. The focus is entirely on vertical transport, but lateral transport and novel planar devices might also benefit from this effort.
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From page 56... ...
OVERALL QUALITY OF THE WORK Overall, the researchers and the management in ARL's Materials Research Campaign are of high caliber. ARL has utilized short-term (5 years)
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From page 57... ...
The software tool set coming from this research is essential for designers, and it may also provide critically sensitive parameters for potential use in process control for commercial partners and suppliers of imaging solutions to the Army, which necessitates engaging with the manufacturers. Other methods of high-strain-rate deformation and fracture and shock wave physics experiments that are beyond just ballistic testing need to be explored either through collaborations or development
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From page 58... ...
For instance, grain boundary modeling and simulation for lightweight protective materials is a fundamental study of B4C that addressed the important issues at the root of its poor ballistic performance but at the same time is developing tools that may be usefully applied to the study of other ceramic materials. The ARLTAB was confronted with the task of assessing programs monolithically, which in general involved determining how successful or how likely the program is to meet it materials development goals.
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From page 59... ...
ARL should create a structure that places all of its Materials Research Campaign programs within the context of a materials development system. On any project, a researcher should be able to clearly explain how their research fits within this system.
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