2013-2014 Assessment of the Army Research Laboratory (2015) / Chapter Skim
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2 Materials Sciences
2 Materials Sciences
Pages 23-56
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From page 23... ...
The 2014 review addressed the areas of electronic materials and devices and structural materials, including materials in extreme environments and multiscale modeling. ARL's materials sciences span the spectrum of technology maturity and address Army applications, working from the state of the art to the art of the possible, according to the ARL.
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From page 24... ...
In expanding innovation, discovering new science and new technology is as rewarding as crafting new uses of existing technologies to develop advanced Army products. Striking a balance between the projects that tackle known unknowns, driven by application and innovation on demand, and the projects that explore unknown unknowns to achieve high-risk and highreward outcomes needs to be an ongoing effort.
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From page 25... ...
It addresses needs in situation awareness and force protection in such areas as on-demand production of biomolecular sensing materials in response to new and emerging hazardous threat materials; functional biomolecular materials that are stable in austere environments; persistent surveillance; and ubiquitous sensing. The project has already done topnotch research by developing iterative and integrated multiscale computational biology capabilities.
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From page 26... ...
For lightweight, quiet, efficient, and reliable power sources that enhance soldier combat capability, the project on fuel cells for military applications tests and evaluates commercial technologies -- namely, direct methanol fuel cells and solid oxide fuel cell (SOFC) systems.
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From page 27... ...
The experimental work conducted in cold spraying, Mg processing, and nanocrystalline metals is excellent, and the researchers have access to centralized characterization facilities. Researchers have made inroads in publishing their results (such as in nanocrystalline metals)
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From page 28... ...
For example, finding 15-unit amino acid sequences that bind strongly to metals and other target compounds will facilitate development of biosensor technology. This research addresses an important need in situation awareness and force protection such as on-demand production of biomolecular sensing materials in response to new and emerging hazardous threat materials.
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From page 29... ...
In Situ Investigation into High-Capacity Alloy-Type Li-Ion Battery Anodes The objective of this work was to systematically investigate by means of atomic force microscopy (AFM) the volume changes occurring during charge and discharge using samples of controlled geometry
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From page 30... ...
In the present work atomic force microscopy was used to image the SEI layer. This appears to be a very fruitful way of investigating the dynamics of SEI layer formation.
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From page 31... ...
It may be important to extend knowledge of mechanisms associated with Pd crystal size, diffusion path through crystals versus grain boundaries, lifetime issues that might be associated with crystal ripening, and alloying effects with the support structure that may lead to degradation on the reformer gas side. There is an extensive literature on Pd membranes and their use in exploring reaction mechanisms associated with surface hydrogen.
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From page 32... ...
Numerical simulations of transient effects play a useful role in modeling transient melting fronts. The project provides a path forward for identifying improved materials with characteristics suitable for Army applications.
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From page 33... ...
While the knowledge of underlying behavior in small-scale systems is presently at an early stage of development, the path forward could include a quantitative modeling component that might grow in time. Photonic Materials and Devices Electromagnetic Modeling of Resonant Quantum-Well Infrared Photodetector Structures The Board noted in its 2011-2012 assessment of the ARL: "Resonator quantum-well infrared photodetectors (QWIPs)
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From page 34... ...
Terahertz Probe of Nitride Semiconductor Opto-electronic Materials and Devices This project described a remarkable collection of scientific results on nitride device and materials characterization and overall was a very promising exploration of new capabilities. The presentation on the project amounted to a catalog of noteworthy achievements but would have been more informative if it had discussed future directions and identified those with the greatest potential.
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From page 35... ...
This finding has already resulted in the publication of several high-visibility articles and is well coupled to the applied project on performance of 2D electronic materials. In the project on understanding the electrical performance of stacked 2D atomic layered materials, the ARL researchers were integrated within a larger team of university collaborators, but they have clearly carved out their own research topics.
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From page 36... ...
Piezoelectric Materials for Frequency-Agile Radio Frequency MEMS Front Ends ARL is a world leader in the piezoMEMS field, providing state-of-the-art materials, fabrication, modeling and simulation, and device prototyping. This mission- and customer-driven project has been ongoing for several years.
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From page 37... ...
Structural Materials Silicon Carbide–Aluminum Metal Matrix Composites Work on SiC-reinforced aluminum matrix composites shows the successful implementation of the more highly loaded composites accomplished by rolling. There is good characterization (in situ scanning electron microscope [SEM]
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From page 38... ...
ARL's cold spray research has advanced from a laboratory-scale demonstration to a pilot-scale operation. Beyond that, the ability to fabricate shaped pieces by combining cold spraying and additive manufacturing technologies has been demonstrated.
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From page 39... ...
The coupling of experimental process development efforts and DFT computational modeling addressing approaches to increase the ductility of W by examining W-rhenium analogs, including W-zirconium and W-titanium, is noteworthy. Energy Coupled to Matter This is a large-scope and long-term project involving a variety of external process parameters that could affect and change the characteristics and properties of materials by modifying their microstructure under a set of target conditions.
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From page 40... ...
Grain Boundaries in Ceramics This program is supported by a complementary ab initio atomic simulation effort. The work to date has been focused on synthesis and exploring different processing routes such as colloidal processing and sputter deposition for depositing amorphous silica and boron suboxide onto the surfaces of boron carbide powder particles.
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From page 41... ...
Processing, where ARL is very strong, is primarily conducted in-house. The materials under investigation are divided into four groups: metals (including Mg by ECAP, nanocrystalline metals via powder and consolidation, and cold spraying technology)
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From page 42... ...
The Biotechnology program is not only newer but also much smaller and has fewer financial resources to build upon than its counterpart branches in the rest of ARL; however, it could make much better effort to connect to and leverage some of the strongest programs in ARL, in particular the Photonics program. The new Biotechnology branch has now a unique opportunity to refine its vision and focus it on collaboration.
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From page 43... ...
Modeling aspects could be brought to bear for predicting hydrogen transfer rates and strain based on pressure differences, among other design issues. It may be important to extend knowledge of the mechanisms associated with Pd crystal size; diffusion paths through crystals versus diffusion paths through grain boundaries; lifetime issues such as might be associated with crystal ripening; and alloying effects with the support structure that may lead to degradation on the reformer gas side.
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From page 44... ...
Businesses understand this kind of promotional activity, and ARL could emulate their approach. Electronic Materials and Devices Low-Dimensional 2D-Atomic Layer Materials In the work on low-dimensionality electronic materials and devices, most of the applications of 2D electronics will require improvements in materials and a large scale-up of materials size, uniformity, and quality to achieve an integration level of at least millions of devices operating at speeds up to 10 GHz to address any meaningful applications.
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From page 45... ...
Structural Materials Silicon Carbide–Aluminum Metal Matrix Composites The challenge for this project is to address critical science and engineering issues that are not addressed by the vast body of literature that already exists in the field of particulate metal matrix composites. This was one of the few posters that explicitly identified the need for a formal feedback mechanism and for optimization to develop robust modeling.
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From page 46... ...
into ion exchange membranes and fuel cells and investigating chemical stability in the actual fuel cell environment. The challenge here will involve establishing a link between chemistry, processing, and microstructure.
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From page 47... ...
Tungsten Alloys Increasing the inherent low fracture toughness of W and its lack of shear-banding driven rod resharpening behavior remain a grand challenge. Exploitation of modeling approaches to understand the atomic bonding and operative mechanisms underpinning these weaknesses in W is a promising modeling and experimental manufacturing process development activity.
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From page 48... ...
This could help to address the lack of understanding of the physical phenomena at multiple scales that govern high-stress and high-strain-rate material performance, resulting from the paucity of validated linkages between experimental and computational research tools at critical length and time scales. Grain Boundaries in Ceramics Boron carbide is an immensely complex material, with unmeasurable (and probably variable)
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From page 49... ...
Multiscale Modeling of Polymers Development of predictive models of the mechanical behavior of UHMWPE will afford improved opportunity to maximize UHMWPE fiber use in armor applications. A challenge in modeling subfiber mechanics is to gain an understanding of the defects within UHMWPE fibers, their length scale, and the linkages between manufacturing and defect distribution and their effects on subfiber and fiber mechanical behavior.
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From page 50... ...
To support development of lightweight, quiet, efficient, and reliable power sources for Army applications to enhance soldier combat capability, the project on fuel cells for military applications tests and evaluates commercially made technologies -- namely, direct methanol fuel cell (DMFC) and SOFC systems.
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From page 51... ...
Overall, in the materials sciences discipline, the quality of the scientific research is excellent, reflecting a broad understanding of the underlying science. There was more effort devoted to understanding and monitoring global research activities than in previous years.
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From page 52... ...
The project on understanding the electrical performance of stacked 2D atomic layered materials is an example of the high quality of the ARL research portfolio in 2D layered electronic materials and devices. In 2011, the investigators switched from studying carbon nanotubes to graphene.
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From page 53... ...
Structural Materials Silicon Carbide–Aluminum Metal Matrix Composites The technical quality of this work is good, with complementary experimental, characterization, and modeling (FEM) components.
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From page 54... ...
Cold Spraying This work had been going on at ARL for a number of years. Its results are significant, and the research is leading to patentable technology and could lead to industrial applications.
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From page 55... ...
The work is off to a good start and is addressing the critical issues of materials synthesis and processing and ensuring that the provenance of the materials is well established before embarking on a detailed mechanical and microstructural characterization of interphase boundaries in boron-icosahedra-based ceramics. The overall technical quality is strong, and the problem is compelling and has significant growth potential.
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From page 56... ...
ARL Enterprise for Multiscale Research in Materials The technical quality is high, but the challenges are daunting as well. Although a significant component of computational modeling is present for the four classes of materials under study (metals, ceramics, polymers, and composites)
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