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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

Raman Scattering Studies in Dilute Magnetic Semiconductor Zn(1-x)Co(x)O

Raman spectra of ZnO and Co substituted Zn1-xCoxO (ZCO) were carried out using the Raman microprobe system with an p.,+ ion laser source of 514.5 nm wavelength. The shift towards the lower frequency side of the nonpolar E210w mode and the broadening due to Co substitution in ZnO were analyzed using the phonon confinement model. The magnetic measurements showed ferromagnetic behavior with the maximum saturation magnetization (1.2micron Beta/ErCo) for 10% Co substitution, which decreased wi th at further increase in Co concentrations. The intensities of E1(LO) at 584 cm-1 and multiphonon modes at 540 cm-1 were increased with an increase in Co substitution. The additional Raman modes in ceramic targets of ZCO spectra for higher concentration of Co substitution (x=15%-20%) were identified to be due to the spinel ZnCo2O4 secondary phase.

Samanta, K.↗
NASA NTRS2004

Nuclear Microprobe using Elastic Recoil Detection (ERD) for Hydrogen Profiling in High Temperature Protonic Conductors

The interaction between hydrogen and various high temperature protonic conductors (HTPC) has not been clearly understood due to poor densification and unreacted secondary phases. the melt-processing technique is used in producing fully dense simple SrCe(0.9)Y (0.10) O(3-delta) and complex Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskites that can not be achieved by solid-state sintering. the possibilities of ion beam analysis have been investigated to quantify hydrogen distribution in HTPC perovskites subjected to water heat treatment. Nuclear microprobe technique is based on the interactions of a focused ion beam of MeV light ions (H-1, H-2, He-3, He-4,.) with the sample to be analyzed to determine local elemental concentrations at the cubic micrometer scale, the elastic recoil detection analysis technique (ERDA) has been carried out using He-4(+) microbeams and detecting the resulting recoil protons. Mappings of longitudinal sections of water treated SrCeO3 and Sr(Ca(1/3)Nb(2/3))O3 perovskites have been achieved, the water treatment strongly alters the surface of simple SrCe(0.9)Y(0.10)O(3-delta) perovskite. From Rutherford Back Scattering measurements (RBS), both Ce depletion and surface re-deposition is evidenced. the ERDA investigations on water treated Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskite did not exhibit any spatial difference for the hydrogen incorporation from the surface to the centre. the amount of hydrogen incorporation for Sr3Ca(1+x)Nb(2+x)O(9-delta) was low and required further development of two less conventional techniques, ERDA in forward geometry and forward elastic diffusion H-1(p,p) H-1 with coincidence detection.

Berger, Pascal↗
NASA NTRS2015

Recognizing Sulfate and Phosphate Complexes Adsorbed onto Nanophase Weathering Products on Mars

Nanophase weathering products (i.e., secondary phases that lack long-range atomic order) have been recognized on the martian surface via orbital observations and in-situ measurements from landed missions. Allophane, a poorly crystalline, hydrated aluminosilicate, has been identified at the regional scale in models of thermal-infrared (TIR) data from the Thermal Emission Spectrometer (TES) and at the local scale from visible/near-IR (VNIR) data from the Compact Reconnaissance Impact Spectrometer for Mars (CRISM) instrument and phase calculations of Alpha Particle X-ray Spectrometer (APXS) data of rocks encountered by the Mars Exploration Rovers (MER) Spirit and Opportunity. Nanophase iron oxides (npOx) have been recognized in rocks and soils measured by the Mössbauer Spectrometer on Spirit and Opportunity. Furthermore, analyses of X-ray diffraction data measured by the CheMin instrument onboard the Mars Science Laboratory rover Curiosity indicate rock and soil samples are comprised of approx. 20-50 wt.% X-ray amorphous materials. Chemical measurements by landed missions indicate the presence of sulfur and phosphorus in martian rocks in soils, and APXS data from Gusev crater demonstrate abundances of up to approx. 5 wt.% P2O5 and approx. 30 wt.% SO3. However, the speciation of phosphorus and sulfur is not always evident. On Earth, phosphate and sulfate anions can be chemisorbed onto the surfaces of nanophase weathering products. This process may also occur on Mars, and calculations of the composition of the amorphous component at Gale crater using CheMin mineral models and APXS data show that amorphous material is enriched in volatiles, including S. Here, we examine the ability to detect chemisorbed sulfate and phosphate complexes by analyzing sulfate- and phosphate-adsorbed nanophase weathering products using instruments similar to those on landed and orbital missions.

Rampe, E. B.↗
NASA NTRS2015

Mineralogy and Petrology of EK-459-5-1, A Type B1 CAI from Allende

Calcium-aluminum-rich inclusions (CAIs) are a type of coarse-grained clast composed of Ca-, Al-, and Mg-rich silicates and oxides found in chondrite meteorites. Type B (CAIs) are exclusively found in the CV chondrite meteorites and are the most well studied type of inclusion found in chondritic meteorites. Type B1 CAIs are distinguished by a nearly monomineralic rim of melilite that surrounds an interior predominantly composed of melilite, fassaite (Ti and Al-rich clinopyroxene), anorthite, and spinel with varying amounts of other minor primary and secondary phases. The formation of Type B CAIs has received considerable attention in the course of CAI research and quantitative models, experimental results and observations from Type B inclusions remain largely in disagreement. Recent experimental results and quantitative models have shown that the formation of B1 mantles could have occurred by the evaporative loss of Si and Mg during the crystallization of these objects. However, comparative studies suggest that the lower bulk SiO2 compositions in B1s result in more prior melilite crystallization before the onset of fassaite and anorthite crystallization leading to the formation of thick melilite rich rims in B1 inclusions. Detailed petrographic and cosmochemical studies of these inclusions will further our understanding of these complex objects.

Jeffcoat, C. R.↗
NASA NTRS2016

Filling in the Gaps: Xenoliths in Meteorites are Samples of "Missing" Asteroid Lithologies

We know that the stones that fall to earth as meteorites are not representative of the full diversity of small solar system bodies, because of the peculiarities of the dynamical processes that send material into Earth-crossing paths [1] which result in severe selection biases. Thus, the bulk of the meteorites that fall are insufficient to understand the full range of early solar system processes. However, the situation is different for pebble- and smaller-sized objects that stream past the giant planets and asteroid belts into the inner solar system in a representative manner. Thus, micrometeorites and interplanetary dust particles have been exploited to permit study of objects that do not provide meteorites to earth. However, there is another population of materials that sample a larger range of small solar system bodies, but which have received little attention - pebble-sized foreign clasts in meteorites (also called xenoliths, dark inclusions, clasts, etc.). Unfortunately, most previous studies of these clasts have been misleading, in that these objects have simply been identified as pieces of CM or CI chondrites. In our work we have found this to be generally erroneous, and that CM and especially CI clasts are actually rather rare. We therefore test the hypothesis that these clasts sample the full range of small solar system bodies. We have located and obtained samples of clasts in 81 different meteorites, and have begun a thorough characterization of the bulk compositions, mineralogies, petrographies, and organic compositions of this unique sample set. In addition to the standard e-beam analyses, recent advances in technology now permit us to measure bulk O isotopic compositions, and major- though trace-element compositions of the sub-mm-sized discrete clasts. Detailed characterization of these clasts permit us to explore the full range of mineralogical and petrologic processes in the early solar system, including the nature of fluids in the Kuiper belt and the outer main asteroid belt, as revealed by the mineralogy of secondary phases.

Zolensky, Mike↗
NASA NTRS2017

Mineralogy of Rock Flour in Glaciated Volcanic Terrains: An Analog for a Cold and Icy Early Mars

Geomorphological and mineralogical data from early Martian surfaces indicate liquid water was present on ancient Mars. The relative surface temperatures, however, remain a subject of debate. Was early Mars warm and wet or cold and icy with punctuated periods of warmth and ice melt? By characterizing the mineralogy and geochemistry of modern icy mafic terrains on Earth, we can search for these characteristics in early Martian terrains to better constrain the early Martian climate. Here, we describe the mineralogy of glacial flour in a modern glaciated volcanic terrain in Oregon, USA. We are particularly interested in secondary phases that form in these environments, and we hypothesize that poorly crystalline phases may preferentially form in these terrains because of the low temperatures and the seasonality of melt water production. A description of the mineralogy of the moraines, the composition of the amorphous materials, and the geochemistry of the glacial melt waters are presented elsewhere. Glacial flour is made up of silt- and clay-sized particles that form from the physical weathering of rock underlying a wet-based glacier as the glacier slides over it. Flour is usually transported from underneath a glacier by melt water streams. The geochemistry of glacial melt water streams has been studied extensively and has been used to infer weathering reactions within glacial systems. However, the mineralogy of these environments, especially on mafic volcanic terrains, is not well studied. Rock flour is a ubiquitous physical weathering product in glaciated terrains and, therefore, affects microbial habitats, stream and lake chemistry, and chemical weathering processes. and by studying the mineralogy of glacial flour, we can better understand geochemical and microbiological processes in subglacial and proglacial terrains.

Rampe, E. B.↗
NASA NTRS2017

Mineral Trends in Early Hesperian Lacustrine Mudstone at Gale Crater, Mars

The Mars Science Laboratory Curiosity rover landed in Gale crater in August 2012 to study the layered sediments of lower Aeolis Mons (i.e., Mount Sharp), which have signatures of phyllosilicates, hydrated sulfates, and iron oxides in orbital visible/near-infrared observations. The observed mineralogy within the stratigraphy, from phyllosilicates in lower units to sulfates in higher units, suggests an evolution in the environments in which these secondary phases formed. Curiosity is currently investigating the sedimentary structures, geochemistry, and mineralogy of the Murray formation, the lowest exposed unit of Mount Sharp. The Murray formation is dominated by laminated lacustrine mudstone and is approx.200 m thick. Curiosity previously investigated lacustrine mudstone early in the mission at Yellowknife Bay, which represents the lowest studied stratigraphic unit. Here, we present the minerals identified in lacus-trine mudstone from Yellowknife Bay and the Murray formation. We discuss trends in mineralogy within the stratigraphy and the implications for ancient lacustrine environments, diagenesis, and sediment sources.

Rampe, E. B.↗
NASA NTRS2019

Constraints on Martian Ancient Magmatic Processes Using Mineral Chemistry of Sedimentary Rocks in Gale Crater, Mars

If Mars has been assumed to be mostly basaltic for a long time, a series of recent discoveries have challenged this simplistic view. Orbital data indicated feldspar-rich rocks in Noachian terrains, likely supporting ancient evolved magmatism. The first indurated regolithic martian meteorite breccia NWA 7034, dated at 4.43 Gyr, contain several leucocratic felsic clasts identified as monzonitic and trachyandesitic, containing feldspars including K-spars and Na-rich plagioclases, pyroxenes, ilmenites and apatites. These clasts have been interpreted as the result of crystallization of a large impact pond. The Mars Science Laboratory rover (Curiosity), travelling within sedimentary bedrock on the floor of the Gale impact crater, discovered feldspar cumulates and a trachyandesite suggesting fractional crystallization of a basaltic melt. In addition, in the Bradbury group of fluvio-deltaic rocks (observed during the 1st 750 sols), sedimentary rocks are mostly comprised of secondary phases and detrital igneous minerals like feldspar, and pyroxene that are thought to come from Noachian-aged magmatic sources, although no definite origin and igneous processes have been inferred.

Payr, V.↗
NASA NTRS2019

Hardness and Microstructure of Binary and Ternary Nitinol Compounds

The hardness and microstructure of twenty-six binary and ternary Nitinol compounds (Ni-Ti, Ni-Ti- Ta, Ni-Ti-Hf, and Ni-Ti-Zr) were studied. A small (50g) button of each compound was produced by vacuum arc melting (VAM). Each alloy was homogenized in vacuum for 48 hr followed by furnace cooling. Specimens from the buttons were then heat treated at 800, 900, 1000 or 1100 °C for 2 hr followed by water quenching. The hardness and microstructure of each specimen was compared to the baseline (55-Nitinol, 55 at.% Ni – 45 at.% Ti, after heat treatment at 900 °C). The results show that sixteen of the studied compounds had higher hardness values than the baseline material with relatively low levels of secondary phase precipitation. Moreover, five of these compounds had hardness values greater than or equal to approximately 660HV (≈58HRC) with essentially no property-degrading precipitation phases.

Stanford, Malcolm K.↗
NASA NTRSDate not supplied

Mars 2020's First Sample: The Fractured Rough Rock Unit on the Floor of Jezero Crater

A central goal of the Mars 2020 mission is to select and cache samples for future return to Earth. The first samples targeted for collection are from the crater-retaining, Crater Floor Fractured Rough (CF-Fr) unit of Stack et al., 2020.The CF-Fr unit is a topographically low unit in the current Jezero setting, likely overlain by morphologically discrete units, including possible Jezero delta deposits and eolian features. CF-Fr is an aerially extensive unit with lobate margins. Two distinct morphologies are observed: a locally-exposed lower expression, with flat relatively horizontal light-toned surfaces and polygonal fracturing, and an upper expression consisting of up to ~5vertical meters of massive, sometimes boulder-producing, material. The locally-exposed lower expression appears to represent a local ground level in which the upper material has been removed. Near the Octavia E. Butler landing site, the lower morphology is exposed as polygonally-fractured, light-toned bedrock that appears to grade continuously into higher-standing massive outcrops, often with no clearly exposed contact. Further south, a darker upper expression of the CF-Fr unit is more distinct and the unit exhibits some horizontal layering. The Perseverance rover will initially sample the flat-lying expression of this unit. Hypotheses for the origin of CF-Fr include fluvial, aeolian, or lacustrine sediment likely derived from the Jezero watershed, and/or pyroclastic material resulting from regional volcanism. Geochronology of the returned sample could be used to help constrain the timing of geological events in Jezero. It may also help constrain stratigraphic relationships with crater-retaining units outside of Jezero within the Nili Planum, which could be used to calibrate the cratering chronology of Mars. Paleomagnetic analyses of an oriented sample could establish the history of the martian dynamo and whether it persisted into the Hesperian. Finally, if present, secondary phases within the primary deposit would help constrain diagenetic conditions and inform post-depositional aqueous and potentially habitable environmental conditions.

Justin I Simon↗
NASA NTRSDate not supplied

Oxygen isotopic mapping of a clast in fragment C0002 from asteroid Ryugu

The samples of Ryugu returned by the Hayabusa2 spacecraft have mineralogy similar to CI chondrites and are dominated by secondary phases(e.g., phyllosilicates, carbonates, magnetite, sulfides) from extensive parent body aqueous alteration. Anhydrous minerals such as olivine, pyroxene, and spinel are rare and exist in phyllosilicate-rich clasts [2-4]. Oxygen isotopic studies of these minerals have shown a bimodal distribution with both 16O-rich and 16O-poor grains. In this study, we conducted NanoSIMS isotopic mapping of a clast found in a fragment of a C0002 grain from Chamber C, which may have derived from the asteroid sub-surface, to characterize small primary minerals

A N Nguyen↗
NASA NTRSDate not supplied

Cr-Rich and Al-Rich Oxide Grains With 16O-Rich Compositions in Ryugu Samples

Samples returned from asteroid Ryugu by JAXA’s Hayabusa2 mission are CI-like, with abundant hydrated and secondary phases [1]. Rare anhydrous minerals occur in the matrix of the major lithology and in chemically distinct clasts. Oxygen isotopic analysis of coarse (> 10 µm) anhydrous Mg-rich silicates revealed a bimodal distribution, with some grains having compositions similar to amoeboid olivine aggregates (AOAs) and others having compositions similar to chondrule phenocrysts [2, 3]. We previously analyzed < 2 µm-sized Mg-rich silicates within a clast that also showed a range of O isotopic compositions (δ18O from -38 to +5 ‰) [4]. In this study, we conducted coordinated isotopic and mineralogical analysis of anhydrous oxide grains found in the matrix of Ryugu samples

A. N. Nguyen↗
NASA NTRS2023

Tribological and Radiation Shielding Response of Novel Titanium-Boron Nitride Coatings for Lunar Structural Components

Aluminum (Al) and titanium (Ti) lightweight alloys play a crucial role in space systems due to their exceptional strength-to-weight ratio. However, their premature failure in the presence of lunar regolith and their lack of neutron shielding ability are significant challenges. To address these issues, we have developed air and vacuum plasma-sprayed hBN (hexagonal Boron Nitride) -reinforced titanium coatings with 2 and 10 vol% of hBN. Tribological studies conducted with JSC-1 A lunar regolith simulant revealed a 90 % reduction in wear volume for the Ti/2 vol% hBN coatings compared to conventional materials due to the synergistic action of harder secondary phases and solid lubrication effect of hBN. Additionally, a 27 % enhancement in radiation shielding is obtained based on the mass absorption coefficient (radiation absorbed per sample density and thickness) for VPS Ti/2 vol% hBN coatings.

Wear↗
DOE OSTI2020

Thallium Bromide Semiconductor Radiation Materials and Detectors Characterization Studies

Two overarching requirements of crucial importance for the commercial and scientific establishment of semiconductor radiation detectors are: (1) exceptionally high-purity crystals with impurity concentrations less than 1 part-per-billion and (2) single crystals that are relatively free from subgrain boundaries, secondary phases, dislocations, and other electrically-active defects. We investigated the properties of thallium bromide (TlBr) material that affect its performance with the goal of increasing the material's commercial viability for radiation detection applications. For this purpose, we used beamlines at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL), performing Micron-scale X-ray Detector Mapping, White Beam X-ray Diffraction Topography, and Micron-scale X-ray Fluorescence. These characterization methods improve the industry's understanding of TlBr and lead to the production of improved instrumentation. In this particular study we report electro-migration measurements of positive-ion Cu, Ag, and Au impurities in TlBr detectors under electric field strengths typically used for device operation. BNL improved TlBr detectors with an electrode design that corrects the response non-uniformities caused by crystal defects. This design can achieve improved energy resolution while using typical-grade, commercial crystals with relaxed quality requirements, thus reducing the overall cost of detectors. Additional characterization will be necessary to fully understand the structure and performance of TlBr with the ultimate goal to achieve the highest energy resolution. Our findings from past work will be presented along with our recommendations for additional investigation.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Ultrasonic characterization of Ti-5Al-5Mo-5V-3Cr

Metastable β titanium alloys such as Ti-5Al-5Mo-5V-3Cr are of increasing interest due to their excellent corrosion resistance, high strength, and in particular, the ability to manipulate microstructure to a high degree to control the mechanical properties of the material. It is therefore important to consider how this manipulation of mechanical properties will affect the inspection of this material with ultrasonic testing both for the purposes of flaw detection and material characterization. The connection between material properties and ultrasonic characterization techniques will be discussed and then dissected in the context of Ti-5553. This metastable alloy was shown to exhibit remarkable variation in microstructure as well as ultrasonic velocity and attenuation demonstrating these techniques as potential candidates for characterizing Ti-5553 and Ti-5553 as a good candidate for aiding in future studies aimed at learning more about the role of secondary phases in ultrasonic wave propagation.

Sunderman, Ruth↗
DOE OSTI2024

Characterization of compositional variation and solidification condition on rapid solidification behavior of beta stabilized titanium

Rapid solidification (RS) is a field of study that has increased in importance due to the rise of additive manufacturing (AM) techniques. The breakdown of equilibrium at the solid-liquid interface results in an inability to use traditional solidification models that have been applied to great success in casting. As such, there is a current need for a high-throughput testing method to screen alloys at rapid solidification conditions without the significant cost for powder atomization. In this work, twin hammer splat quenching (SQ) is utilized and theoretically developed as a technique uniquely placed to test alloy systems for AM applications. Using analytical thermal spray models and numerical heat transfer simulations, the cooling rate and solidification conditions of splat quenching are compared across several parameters to evaluate the key parameters for generating cooling rates relevant to AM process. Once a framework for the cooling rates and relevancy of SQ are developed, SQ was used to process alloy compositions in the Ti5553 alloy space (AMS 7026) to study the formation of detrimental secondary phases occurring upon rapid quenching from the melt. A martensitic phase is found to occur at the lower end of the standard, but the composition listed in the standard were found to be safe. Finally, the rapid solidification behavior of Ti-5553 is evaluated by comparing splat quenching, laser welding, and plasma atomization that offer a wide window of solidification conditions. The segregation and solidification structure are analyzed and compared to models to provide a deeper understanding of the solidification behavior of beta stabilized titanium alloys.

Williamson, Christopher J.↗
DOE OSTI2025

Time at Temperature Abstract and Intern Poster

Current NRC regulations for BWR operations dictate that any occurrence reaching the point of Departure from Nucleate Boiling (DNB) disqualifies the use of the fuel rod for further reactor operation. That criteria does not account for duration of rate of the power increase, the corresponding effects on material properties or rewetting that may occur. Previous Anticipated Operational Occurrences (AOOs) show short durations power increase that may require limited amounts of heat removal. Industrial experience has shown evidence that fuel can reach dryout yet continue to safely operate in regular reactor conditions. The gap in research into such occurrences is the motivation for a series of experiments, including this current work. Time-at-Temperature experiments aim to identify and characterize the microstructural changes in Zircaloy-2 under oxygen-free high temperatures. This work uses the FlashDSC instrument to rapidly ramp up and down the temperature of a focus ion beam (FIB) prepared large area lift-out (LALO) of Zircaloy-2 at a rate of 10,000 K/s to desired values. The focus is to characterize the microstructure evolution, if any, of Zircaloy-2 that may impact its performance under typical BWR conditions. This characterization includes analyzing grain structure and size, secondary phase particle (SPPs) size, shape, composition, and location using Transmission Electron Microscopy (TEM). Further data collection and analysis is in progress including diffraction pattern indexing and 4D STEM processing. While current results focus on the testing and characterizing unirradiated material, future plans include expansion to irradiated material to explore the effects of rapid transition rates seen in DNB and dryout conditions on irradiationg damage and defect annealing.

36 - MATERIALS SCIENCE↗
DOE OSTI2022

Effect of secondary gas-phase reactions (SGR) in pyrolysis of carbon feedstocks for anisotropic carbon materials production – 2: Effects of SGR on tars produced from varying ranks of coal

Herein, this work explores the extent to which secondary gas-phase reactions (SGR) in pyrolysis can be used to modify coal tar chemistries from coals of different ranks in favor of improved anisotropy formation in their respective pitches. Pyrolysis was performed on four different coals of varying bituminous rank (Utah Sufco, Wyoming PRB Black Thunder, Illinois #6, and West Virginia Flying Eagle), with SGR temperatures ranging from 800 to 900° C and nominal SGR gas-phase residence times from 1 to 2.5 s. The oxygen content, aliphatic content, and molecular weight distributions of the coal tar samples were measured to indicate the changes with increasing levels of SGR, and microscopy was also used to measure changes in anisotropy formation in the resulting pitch samples. Generally, for all coals tested, increased levels of pyrolysis SGR led to decreased oxygen and aliphatic content, increased molecular weight sizes, and improved anisotropy formation. However, it was clear that the extent of these property changes depended on the chemistry and rank of the starting coal feedstock. Despite the relatively high rank of the Illinois #6 coal, its respective pitch samples performed poorly in improving anisotropy formation, due to its high sulfur content. The PRB, Sufco, and Flying Eagle coals performed better in their anisotropy formation than Illinois #6, depending on their respective coal ranks. Statistical analysis (analysis of variance, ANOVA) performed on the sample characterization data also suggests that SGR temperature is consistently the most dominant and significant effect on the resulting coal products.

01 COAL, LIGNITE, AND PEAT↗