Materials

Pulsed Microwave Plasma Instrumentation for Investigation of Plasma-Tuned Multiphase Combustion

Strategies to control solid rocket propellant regression rate require a robust throttling technique applicable to high performance propellant formulations. Currently, several methods to control and throttle either motors or subscale propellant strands exist, including chamber pressure control (e.g. pintle nozzles or rapid depressurization quench), infrared laser irradiation of the burning surface to increase burning rates, development of inherently unstable combustion chamber geometries (producing either local pressure or velocity perturbations), and electrically sensitive hydroxylammonium nitrate (HAN)-based formulations in which burning rate is controlled by a voltage potential. However, these techniques are limited in that they either can only be used with low flame temperature (low specific impulse) propellants, result in low propulsion system mass fraction (pintle), are only capable of producing a single perturbation, or are formulation specific.

Posted in: Briefs, Aerospace, Energy, Materials, Power Transmission, Propulsion, RF & Microwave Electronics, Instrumentation
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NIF Experiments Support Warhead Life Extension

It was a normal morning for design physicist Madison Martin at Lawrence Livermore National Laboratory (LLNL). At 7:45 a.m., she settled into her classified workstation with a cup of tea to check the results of a numerical calculation she ran overnight. If the calculations proved correct, the experiment she was designing on the National Ignition Facility (NIF) would deliver the data her colleagues needed to verify that a refurbished nuclear warhead would perform as expected.

Posted in: INSIDER, News, Data Acquisition, Defense, Materials, Data Acquisition, Detectors, Sensors
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Discovery Could Lead to Munitions That Go Further, Much Faster

Researchers from the U.S. Army and top universities discovered a new way to get more energy out of energetic materials containing aluminum, common in battlefield systems, by igniting aluminum micron powders coated with graphene oxide. This discovery coincides with the one of the Army's modernization priorities: Long Range Precision Fires. This research could lead to enhanced energetic performance of metal powders as propellant/explosive ingredients in the Army's munitions.

Posted in: INSIDER, News, Defense, Alternative Fuels, Energy, Energy Efficiency, Energy Storage, Materials, Propulsion
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Porous and Stiff Material for Aircraft Lightweighting

Researchers have developed and manufactured a family of architectures that maximizes the stiffness of porous, lightweight materials. 3D printing and other additive production techniques make it possible to manufacture materials with internal structures of previously unimaginable complexity. Achieving this requires that the internal structures be intelligently organized for maximum efficiency.

The stiffness in the material’s interior is achieved through plate-lattices rather than trusses. These structures that are up to three times stiffer than truss-lattices of the same weight and volume.

Posted in: INSIDER, News, Defense, Composites, Materials
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Metal Additive Manufacturing

Additive manufacturing (AM) – the process of building up solid layers of material to form a finished solid part — is an emerging and exciting technical discipline. Also referred to as “3D printing,” many misconceptions exist about the capabilities and promises of the technology.

Posted in: Articles, Aerospace, 3 D Printing & Additive Manufacturing, Manufacturing & Prototyping, Rapid Prototyping & Tooling, Materials, Metals, Plastics, Machinery, Mechanical Components
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Microstructural and Mechanical Characterization of 2-D and 3-D SiC/SiNC Ceramic-Matrix Composites

The purpose of this endeavor was to investigate the effect of 3-D weave architecture on PIP-processed ceramic-matrix composites (CMC). Microstructural studies were performed to document the resulting microstructure and mechanical testing was performed to determine the high-temperature durability of the five different variants of SiC/SiNC CMC investigated.

Posted in: Briefs, Aerospace, Imaging, Ceramics, Composites, Materials, Mechanical Components
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Evaluation of Peel Ply Surface Preparation of Composite Surfaces for Secondary Bonding

Lightweight composite structures offer significant long-term cost-saving opportunities for the U.S. Army as replacements for traditional metal structures. However, high-strength economical bonding processes must be developed to join composites in order for them to be viable replacements. The Army is exploring approaches, also under evaluation in the commercial aerospace industry, to reduce the process steps associated with composite bonding.

Posted in: Briefs, Aerospace, Defense, Manufacturing & Prototyping, Ceramics, Materials, Metals, Joining & Assembly, Mechanical Components
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Enhanced Contacts for Inverted Metamorphic Multi-Junction Solar Cells Using Carbon Nanotube Metal Matrix Composites

In order to address issues related to mechanical and vibrational stresses that are commonly experienced in mounting, launch, and deployment of spacecraft, metal matrix composite (MMC) electrodes were fabricated with carbon nanotubes (CNTs) as reinforcement. The research plans were centered on first developing and selecting appropriate processes for fabricating CNT-MMCs based on characterization of their material properties, followed by optimizing MMC designs based on electrical testing under stress. Efforts in the program were also directed toward implementing the CNT-MMCs into solar cell device processing in a process compatible with standard clean room procedures.

Posted in: Briefs, Aerospace, Defense, Energy, Energy Efficiency, Energy Storage, Renewable Energy, Solar Power, Materials, Metals, Mechanical Components, Nanotechnology, Measuring Instruments, Test & Measurement
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Fiber-Reinforced Thermoplastic Composites

Reinforcing polymers with strong/stiff fibers is nothing new. Such materials have been used pretty much since aircraft were first created. In those pioneering days, wings were reinforced with woven cotton, or silk fabric skins, impregnated with nitrocellulose ‘dope’ to seal against the wind, and laminated wood was reinforced with fabric bonded with adhesive. Although there have been a myriad of developments along the way from those early days to where we are now in the 21st century, the principles of reinforcement are much the same.

Posted in: Articles, Aeronautics, Aerospace, Aviation, Defense, Thermal Management, Manufacturing & Prototyping, Composites, Materials, Metals, Plastics
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Lightweighting Parts Using 3D Metal Printing

Metal additive manufacturing (3D printing), also known as Direct Metal Laser Sintering (DMLS) or Powder Bed Fusion (PBF), is changing the way metal parts are designed and produced. New software, processes and materials are redefining manufacturing value equations for specific types of parts, which can lead to improvements on existing products, new business models and new markets.

Posted in: Articles, Aerospace Manufacturing and Machining, Aeronautics, Aerospace, Aviation, Defense, 3 D Printing & Additive Manufacturing, Manufacturing & Prototyping, Materials, Metals, Computer-Aided Design (CAD), Computer-Aided Engineering (CAE), Computer-Aided Manufacturing (CAM), Simulation Software, Software
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