Materials

3D Meta-Optics for High-Energy Lasers

The scope of this research radically changed the way novel components are designed and fabricated for high-energy applications. This 3D Meta-Optics platform was, and is, essentially engineering the electromagnetic fields in 3D dielectric structures. The results have provided a class of transformational optical components that can be integrated at all levels throughout a high-energy laser system.

Posted in: Briefs, Aerospace, Defense, Manufacturing & Prototyping, Materials, Lasers & Laser Systems, Optical Components, Optics, Test & Measurement
Read More >>

Thermal Conductivities of Some Polymers and Composites

Thermoset polymers are good electrical insulators that are used in applications ranging from electronics to composite armor. They are rather poor thermal conductors, however.

Posted in: Briefs, Aerospace, Defense, Electronic Components, Electronics, Electronics & Computers, Thermal Management, Composites, Materials, Instrumentation, Measuring Instruments, Test & Measurement
Read More >>

Hybrid Ultra-Low VOC and Non-HAP Rain Erosion Coatings

Numerous military aircraft and shipboard surfaces, such as radomes, antennas, gun shields, wing leading edges, and helicopter blade leading edges, are coated with a specialized erosion-resistant protective coating possessing strict performance requirements. These protective coatings must provide excellent rain erosion resistance, superior mechanical properties, good adhesion to the substrate and meet a host of other metrics outlined in MIL-PRF-32239 and SAE AMS-C- 83231A.

Posted in: Briefs, Aerospace, Defense, Coatings & Adhesives, Mechanical Components
Read More >>

Electrical Characterization of Crystalline UO2, THO2 and U0.71TH0.29O2

Tracking and identifying radiation sources in the age of nuclear proliferation and well- resourced non-state actors is a national priority. Current neutron detection methods favor large detector volumes and long data collection times. Additionally, portable neutron detection methods have persistent problems with low signal-to-noise (small pulse height) and require large applied voltages.

Posted in: Briefs, Aerospace, Defense, Materials, Mechanical Components, MEMs, Semiconductors & ICs, Data Acquisition, Detectors, Sensors
Read More >>

Matrix-Free Assisted Laser Desorption Ionization Using Metal-Organic Frameworks

Matrix-assisted laser desorption/ionization (MALDI) is a soft ionization technique that is widely applied in the characterization of large biomolecules using various mass spectrometry (MS) analyzers, specifically, time-of-flight (TOF) analyzers. The MALDI process involves the deposition of an analyte solution onto a metal substrate before the addition of a matrix. The matrix/analyte dry spot is exposed to a UV laser, and the laser energy that is absorbed by the matrix/analyte is converted into heat energy that initiates charge transfer, which results in the desorption of the matrix and analyte molecules in ionized form. The positive ions are then accelerated through a vacuum into MS analyses.

Posted in: Briefs, Aerospace, Defense, Materials, Metals, Mechanical Components, MEMs, Data Acquisition, Sensors, Inspection Equipment, Instrumentation, Measuring Instruments, Monitoring, Test & Measurement
Read More >>

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
Read More >>

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
Read More >>

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
Read More >>

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
Read More >>

Burner Rig Testing of A500® C/SiC

There is growing interest in developing, testing, and deploying ceramic-matrix composites (CMCs) into commercial and military aerospace gas turbine engines due to their durability under extreme conditions and weight-savings potential. For military applications, the focus is on the afterburning section of the turbine engine, including the flameholder, augmentor liner, and both the convergent and divergent segments of the exhaust nozzle. These are demanding applications because of the high temperatures and rapid thermal cycles.

Posted in: Briefs, Aerospace, Composites, Materials, Instrumentation, Measuring Instruments, Monitoring, Test & Measurement
Read More >>