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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,207 records · Page 67
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Low earth orbit durability evaluation of Haynes 188 solar receiver material

The effects of elevated-temperature vacuum and elevated-temperature atomic oxygen exposure on the mass, surface chemistry, surface morphology, and optical properties of Haynes 188, a possible heat receiver material for space-based solar dynamic power systems, have been studied. Pristine and surface modified Haynes 188 were exposed to vacuum less than or equal to 10 exp -6 torr at 820 C for 5215.5 h, and to atomic oxygen in an air plasma asher at 34 and 827 C for fluences up to 5.6 x 10 exp 21 atoms/sq cm. Results obtained indicate that vacuum heat treatment caused surface morphology and chemistry changes with corresponding optical property changes. Atomic oxygen exposure caused optical property changes which diminished with time. Mass changes are considered to be negligible for both exposures.

De Groh, Kim K.↗
NASA NTRS1993

An overview of the evaluation of oxygen interaction with materials-third phase (EOIM-III) experiment - Space Shuttle Mission 46

An overview of EOIM-III, designed to produce benchmark atomic oxygen reactivity data is presented. Ambient density measurements are conducted using a quadrupole mass spectrometer calibrated for atomic oxygen measurements in a unique ground-based test facility. The combination of these data with the predictions of ambient density models permits an assessment of the accuracy of measured reaction rates on a variety of materials, many of which have never been tested in LEO previously.

Leger, Lubert J.↗
NASA NTRS1992

Nondestructive evaluation of a ceramic matrix composite material

Monolithic ceramic materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited because of their sensitivity to small imperfections. To overcome this extreme sensitivity to small imperfections, ceramic matrix composite materials have been developed that have the ability to withstand some distributed damage. A borosilicate glass reinforced with several layers of silicon-carbide fiber mat has been studied. Four-point flexure and tension tests were performed not only to determine some of the material properties, but also to initiate a controlled amount of damage within each specimen. Acousto-ultrasonic (AU) measurements were performed periodically during mechanical testing. This paper will compare the AU results to the mechanical test results and data from other nondestructive methods including acoustic emission monitoring and X-ray radiography. It was found that the AU measurements were sensitive to the damage that had developed within the material.

Grosskopf, Paul P.↗
NASA NTRS1995

Engineering development program of a closed aluminum-oxygen semi-cell system for an unmanned underwater vehicle: An update

Most emerging unmanned undersea vehicle (UUV) missions require significantly longer range and endurance than is achievable with existing battery technology. The Aluminum-Oxygen (Al-O2) semi-cell is a candidate technology capable of providing a significant improvement in endurance compared to the silver-zinc battery technology currently used in UUVs and compares favorably to other proposed UUV power systems not only in performance, but also in safety and logistics. An Al-O2 semi-cell system is under development by Loral Defense Systems-Akron (Loral) for the ARPA/Navy 44 in. diameter UUV test vehicle. The power plant consists of a cell stack, gas management, oxygen storage, electrolyte management, coolant and controller subsystems, designed to replace the existing silver-zinc battery and meet existing weight, volume, electrical and thermal requirements, therefore minimizing modifications to the UUV. A detailed system design is complete. A component and material endurance test to evaluate compatibility and reliability of various material arid components is complete. Sub scale (Short stack) system testing is completed. A full-scale demonstration unit is now under construction in the second half of 1995. The full scale demonstration test will simulate environmental conditions of the operational system. This paper summarizes the results of the extensive short stack and endurance test programs, describes the plan for full-scale testing, and concludes with a brief discussions of future directions for this technology. This program is sponsored by ARPA Maritime Systems Technology Office under NASA contract NAS3-26715.

Gregg, Dane W.↗
NASA NTRS1996

Engineering Development Program of a Closed Aluminum-Oxygen Semi-cell System for an Unmanned Underwater Vehicle: An Update

Most emerging unmanned undersea vehicle (UUV) missions require significantly longer range and endurance than is achievable with existing battery technology. The Aluminum-Oxygen (Al-O2) semi-cell is a candidate technology capable of providing a significant improvement in endurance compared to the silver-zinc battery technology currently in use in UUVs and compares favorably to other proposed UUV power systems not only in performance, but also in safety and logistics. An Al-O2 semi-cell system is under development, consisting of a cell stack, gas management, oxygen storage, electrolyte management coolant and controller subsystems. It is designed to replace the existing silver-zinc battery and meet existing weight, volume, electrical and thermal requirements, therefore minimizing modification to the UUV. A detailed system design is complete. A component and material endurance test to evaluate compatibility and reliability of various materials and components is complete. Sub=scale (short stack) system testing is complete. A full-scale demonstration unit is now under construction for testing in the second half of 1995. The full scale demonstration test will simulate environmental conditions of the operational system. This paper summarizes the results of the extensive short stack and endurance test programs, describes the plan for full-scale testing, and concludes with a brief discussion of future directions for this technology.

Gregg, Dane W.↗
NASA NTRS1997

Preparation, Fabrication, and Evaluation of Advanced Polymeric and Composite Materials

The thesis titles are given below: physical and mechanical behavior of amorphous poly(arylene ether-co-imidasole)s and poly(arylene ether-co-imidasole) modification epoxies; the requirements of patentability as applied to the chemical arts; fabrication of thermoplastic polymer composite ribbon; blend of reactive diluents with phenylethynyl-terminated arylene ether oligomers; the synthesis, characterization, and application of ether-containing polyimides; the synthesis of reflective and electrically conductive polyimide films via an in-situ self-metalization procedure using silver (I) complexes; the thermal cure of phenylethynyl terminated polyimides and selected model compounds; and the synthesis, characterization, and molecular modeling of cyclic arylene ether oligomers.

Orwoll, Robert A.↗
NASA NTRS2001

ZBLAN Viscosity Instrumentation

The past year's contribution from Dr. Kaukler's experimental effort consists of these 5 parts: a) Construction and proof-of-concept testing of a novel shearing plate viscometer designed to produce small shear rates and operate at elevated temperatures; b) Preparing nonlinear polymeric materials to serve as standards of nonlinear Theological behavior; c) Measurements and evaluation of above materials for nonlinear rheometric behavior at room temperature using commercial spinning cone and plate viscometers available in the lab; d) Preparing specimens from various forms of pitch for quantitative comparative testing in a Dynamic Mechanical Analyzer, Thermal Mechanical Analyzer; and Archeological Analyzer; e) Arranging to have sets of pitch specimens tested using the various instruments listed above, from different manufacturers, to form a baseline of the viscosity variation with temperature using the different test modes offered by these instruments by compiling the data collected from the various test results. Our focus in this project is the shear thinning behavior of ZBLAN glass over a wide range of temperature. Experimentally, there are no standard techniques to perform such measurements on glasses, particularly at elevated temperatures. Literature reviews to date have shown that shear thinning in certain glasses appears to occur, but no data is available for ZBLAN glass. The best techniques to find shear thinning behavior require the application of very low rates of shear. In addition, because the onset of the thinning behavior occurs at an unknown elevated temperature, the instruments used in this study must provide controlled low rates of shear and do so for temperatures approaching 600 C. In this regard, a novel shearing parallel plate viscometer was designed and a prototype built and tested.

Kaukler, William↗
NASA NTRSDate not supplied

Promoted Combustion Behavior of 316 Stainless Steel and 6061 Aluminum Alloys in Elevated Pressure Nitrox Environments

Promoted combustion testing (outlined in the ASTM G124 “Standard Test Method for Determining the Combustion Behavior of Metallic Materials in Oxygen Enriched Atmospheres”) refers to a useful testing method to evaluate how metallic materials will behave when combusted in environments with high oxygen concentrations, elevated pressure, or both. These tests yield data which is useful for engineers and scientists from a variety of industries who need and rely on oxygen systems. Oxygen Compatibility Assessments (OCA’s) are vital for ensuring that materials will be safe for use, and these assessments rely on data from OCA’s or interpolation if a desired pressure/concentration is outside of previously tested bounds. It was identified that these bounds leave out significant areas of data for materials which are tested at high pressures (above 1500 psi) and variable oxygen concentrations (with nitrogen as the diluent gas). For this reason, the authors posited that conducting promoted combustion testing on materials above 1500 psi and in various concentrations of oxygen would be incredibly useful in future analyses for oxygen compatibility with similar environments (such as breathing air) as well as for further understanding of how materials behave at very high pressures (such as 10000 psi). Two materials were selected which are commonly used in industry today - 316 stainless steel and 6061 aluminum – and they were tested and analyzed for the purposes of this study.

oxygen compatibility↗
NASA NTRSDate not supplied

Development of a Generic Small-Satellite Payload for On-Orbit Characterization and Evaluation of Novel Radiation-Shielding Materials

There is a need for lightweight and novel radiation shielding for small satellites operating in LEO and beyond. Current state of the art shielding materials include aluminum and polyethylene, or no shielding due to weight and dimensional considerations. New materials are being developed which may offer advantages over current options. These materials include novel lightweight composites impregnated with metallic nanoparticles, chitin-derived bioplastics, and aerogel-family materials. A compact experiment platform that allows the simultaneous testing of a number of potential shielding materials will be useful in comparing and validating them. The effort now underway seeks to develop a miniaturized, modularized payload which will allow testing of materials using 1U CubeSat form factor modules with four scintillator radiation detectors arrayed behind four sample material windows exposed to space. The first proposed mission will utilize a 2U payload volume to host two test quartets enabling eight materials to be tested. Such a test platform can potentially be used as a hosted payload on a variety of spacecraft to test other materials in the future.

Avery D Brock↗
NASA NTRSDate not supplied

Development of a Universal Small-Satellite Payload for On-Orbit Characterization and Evaluation of Novel Radiation-Shielding Materials

There is a need for novel lightweight radiation shielding materials for small satellites operating in LEO and beyond. Current commonly used shielding materials include aluminum and polyethylene, though often no additional shielding than that provided by structure is used due to mass and dimensional constraints. New materials are being developed which may offer advantages over these current solutions. These materials include novel lightweight composites impregnated with metallic nanoparticles, chitin-derived bioplastics, and aerogel-family materials. A compact CubeSat experiment payload that allows the simultaneous testing of numerus potential shielding materials would be useful to enable material comparison and efficacy validation. An effort currently underway seeks to develop such a miniaturized modularized payload, which will enable the testing of materials in 1U CubeSat form factor modules, with each module hosting four scintillator radiation detectors arrayed behind four sample material windows exposed to space. The first proposed mission will utilize a 2U payload volume to host two test quartets enabling eight materials to be tested. Such a test platform can potentially be used as a hosted payload on a variety of spacecraft to test additional materials in the future

Luke Idziak↗
DOE OSTI2020

Evaluation of radiation hardness of semiconductor materials against alpha particles for an API detector

An Associated Particle Imaging (API) system consists of a high vacuum chamber where deuterium ions are accelerated on a tritium-loaded target, resulting in alpha particles and neutrons emitted back-to-back, the latter escaping the chamber and used, for example, for tomography of a high-Z sample. An accurate determination of the alpha position is crucial to determine the trajectory of the neutron. Existing API systems have several limitations which a semiconductor-based API detector placed inside the vacuum chamber should not present. The semiconductor material can be either silicon or diamond. In particular, large and fast signals are generated by the alpha interactions in these materials. A pixelated API detector will measure the time and hit position of the alphas produced in the reaction. However, during the lifetime of the generator, the semiconductor detector will be exposed to an intense flux of alpha particles that will degrade its performance over time. To assess the radiation hardness of silicon and diamond against the alpha particles, we exposed single diodes made of either of the two materials to a 5 MeV alpha flux generated by an 241Am radioactive source. During irradiation, the diodes were biased and mounted on current-sensitive preamplifier boards. We have therefore been able to measure insitu the evolution of the waveforms as the damage was accumulating in their substrates.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Detection of Defects in Additively Manufactured Metallic Materials with Machine Learning of Pulsed Thermography Images

Additive manufacturing (AM) is an emerging method for cost-efficient fabrication of nuclear reactor parts. AM of metallic structures for nuclear energy applications is currently based on laser powder bed fusion (LPBF) process, which can introduce internal material flaws, such as pores and anisotropy. Integrity of AM structures needs to be evaluated nondestructively because material flaws could lead to premature failures due to exposure to high temperature, radiation and corrosive environment in a nuclear reactor. Quality control (QC) requires nondestructive evaluation (NDE) of actual AM structures. Pulsed thermography is a potentially promising QC technique because it is scalable to arbitrary structure size. However, detection sensitivity of this method is limited by noises. We investigate separation of signal from noise in thermography images using several machine learning (ML) methods, including new spatio-temporal blind source separation (STBSS) and spatio-temporal sparse dictionary learning (STSDL) methods. Performance of the ML methods is benchmarked using thermography data obtained from imaging stainless steel 316L and Inconel 718 specimens produced LPBF method with imprinted calibrated porosity defects. The ML methods are ranked by F-score and execution runtime. The ML methods with higher accuracy require longer run time. However, this runtime is sufficiently short to perform QC within a realistic time frame.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Evaluating the Thickness and Stratigraphy of Ejecta Materials at the Chang’e-4 Landing Site

The landing site of China’s Chang’e-4 (CE-4) probe is located on the mare basalts on the floor of the Von Kármán crater on the lunar far side. The Von Kármán crater is inside the ancient and highly cratered South Pole–Aitken basin, which has experienced complex emplacement sequences of both near and distant ejecta materials. These issues complicated the interpretation of the CE-4 surface in situ measurements of the visible and near-infrared spectrometer and the lunar penetrating radar (LPR) onboard Yutu-2 rover. To evaluate the sources and amounts of all principle foreign materials at the CE-4 landing site, we thoroughly examine the ejecta delivered by crater-forming events that occurred later than the formation of the mare basalts at the CE-4 landing site. We found a total of 16 craters that may have delivered ejecta thicker than 10 cm level superposed on the mare basalts at the CE-4 landing site. Crater Finsen, Von Kármán L, Von Kármán L′, and Maksutov are the top four major foreign material sources, and each of them contributed ejecta thicker than 1 m. Our surveys confirm that the ejecta from Finsen crater are the most dominant foreign materials in the uppermost few meters at the CE-4 landing site and the total impact ejecta deposited upon the mare basalts at the landing site is estimated to be thinner than 30 m. We found that the estimations from Pike’s model are the most consistent with the Yutu-2 LPR observations.

58 GEOSCIENCES↗
NASA NTRS2019

Evaluation of Impact Energy Attenuators and Composite Material Designs of a UAM VTOL Concept Vehicle

The development of Vertical Take-off and Landing (VTOL) vehicles for the Urban Air Mobility (UAM) markets presents a need for light weight vehicle structures with effective occupant protection capabilities. The National Aeronautics and Space Administration (NASA) has been working to fill that need, recently developing a cadre of concept vehicles to help characterize UAM design feasibility. This paper describes a study, using these concept vehicles, to evaluate the use of advanced composite structure and energy attenuating designs in the UAM vehicle design space. A finite element model (FEM) of a single passenger quadrotor concept vehicle was developed in LS-Dyna® and simulated under nominal and off-nominal vertical impact conditions. A variety of energy attenuating design mechanisms were implemented within this model to quantify their effectiveness in improving occupant safety. The use of carbon composites in both the energy attenuation mechanisms and vehicle structure was evaluated. The results of this study found significant reduction in occupant injury risk with the implementation of energy absorbing composite crush tubes and landing gear within the vehicle design. Additionally the use of a carbon fiber as a structural material was found to provide significant weight reduction while maintaining similar occupant loads to that predicted with an aluminum structure. This work provides a preliminary evaluation of design mechanisms and materials that may be used to optimize occupant protection capabilities within the UAM market.

Putnam, Jacob↗
DOE OSTI2026

Evaluating Technology Adoption Risks in Early-Stage Materials Research

Development of new technologies often begins with fundamental materials science research. Decisions at this stage can shape factors related to the eventual adoption readiness of the technology, such as process scalability or materials availability. Here we present the early-Stage Technology Evaluation for Adoption Risks (STEAR) framework as a method for qualitatively assessing metrics spanning four categories of adoption risks: value proposition, market acceptance, resource maturity, and license to operate. We conduct a case study applying STEAR to different methanol production processes at a range of technology readiness levels and demonstrate how the assessment identifies key challenges related to adoption readiness. Finally, we discuss efforts to expand the applicability and utility of STEAR, including focus group feedback and complementary quantitative analysis methods.

36 MATERIALS SCIENCE↗