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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2015

Kennedy Space Center Press Site (SWMU 074) Interim Measure Report

This report summarizes the Interim Measure (IM) activities conducted at the Kennedy Space Center (KSC) Press Site ("the Press Site"). This facility has been designated as Solid Waste Management Unit 074 under KSC's Resource Conservation and Recovery Act Corrective Action program. The activities were completed as part of the Vehicle Assembly Building (VAB) Area Land Use Controls Implementation Plan (LUCIP) Elimination Project. The purpose of the VAB Area LUCIP Elimination Project was to delineate and remove soil affected with constituents of concern (COCs) that historically resulted in Land Use Controls (LUCs). The goal of the project was to eliminate the LUCs on soil. LUCs for groundwater were not addressed as part of the project and are not discussed in this report. This report is intended to meet the Florida Department of Environmental Protection (FDEP) Corrective Action Management Plan requirement as part of the KSC Hazardous and Solid Waste Amendments permit and the U.S. Environmental Protection Agency's (USEPA's) Toxic Substance Control Act (TSCA) self-implementing polychlorinated biphenyl (PCB) cleanup requirements of 40 Code of Federal Regulations (CFR) 761.61(a).

Measures↗
DOE OSTI2018

Hot Isostatically Pressed Ceramic Waste forms for High Dose Spent Adsorbents - 18129

Decommissioning and clean-up of nuclear facilities requires the development of new technologies to condition radioactive wastes, producing passively safe waste packages of minimal volume, to reduce storage and disposal costs. We have applied hot isostatic pressing to demonstrate conceptual waste forms for high dose spent adsorbents (i.e. ion exchange materials) present on the Sellafield site, UK, and Fukushima Daiichi site, Japan. These radioactive wastes pose several challenges which demand early conditioning to produce a passively safe wasteform, including: a wet and granular nature, and hence dispersible as a result of loss of containment; a very high dose rates as a result of their selectivity for short lived radionuclides (e.g. Sr-90, Cs-137, Co-60); radiogenic self-heating, as a result of the concentration of such lived radio nuclides; hydrogen production as a result of radiolysis of entrained water [1]. Here, we demonstrate the conversion of natural inorganic ion exchange materials into multiphase ceramic waste forms, achieving a waste loading of 100 wt.% and density in excess of 97% theoretical. High resolution thermogravimetric analysis coupled with mass spectroscopy was utilised to characterise the evolution of water and volatiles during the in-can bake out step, prior to the HIP cycle. This allowed optimisation of the bake out parameters (temperature, time and vacuum) to enable complete removal of water and volatiles, affording ceramic bodies with minimal residual porosity by hot isostatic pressing at 1250 deg. C for 4 h in stainless steel canisters. Characterisation of the ceramic waste forms by SEM /EDX and X-ray diffraction revealed the nuclides of concern to be incorporated within well-known natural mineral and synthetic phases, with Cs partitioning into the K-feldspar. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

The Evolution of Hot-Isostatic Pressing for the Treatment of Radioactive Wastes - 18276

Hot-isostatic Pressing (HIPing) was first developed by Battelle in the 1950's for applications in the nuclear program. The use of HIPing as a means of treating radioactive wastes was first proposed and patented in Sweden in the 1970's and subsequently gained traction in the US, where throughout the 1980's and 90's work was undertaken at Rockwell, Lawrence Livermore National Laboratory (LLNL), and Idaho National Laboratory (INL) on waste-forms for US Defense wastes. This development was coupled with front-end processing options leading to conceptual plant designs which included hot-cell layouts and costings. Industrial maturation of hot-isostatic press (HIP) technology over the last 20+ years has seen it increasingly become a candidate for treating a variety of waste streams. In this paper, we discuss HIP concepts for treating radioactive wastes, present some recent work undertaken by the authors to demonstrate the feasibility of HIPing for sludge wastes and ion exchangers, and discuss the options and technology challenges for implementation. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Synchrotron X-ray microbeam diffraction measurements of full elastic long range internal strain and stress tensors in commercial-purity aluminum processed by multiple passes of equal-channel angular pressing

Synchrotron X-ray microbeam diffraction was used to measure the full elastic long range internal strain and stress tensors of low dislocation density regions within the submicrometer grain/subgrain structure of equal-channel angular pressed (ECAP) aluminum alloy AA1050 after 1, 2, and 8 passes using route B C . This is the first time that full tensors were measured in plastically deformed metals at this length scale. The maximum (most tensile or least compressive) principal elastic strain directions for the unloaded 1 pass sample for the grain/subgrain interiors align well with the pressing direction, and are more random for the 2 and 8 pass samples. The measurements reported here indicate that the local stresses and strains become increasingly isotropic (homogenized) with increasing ECAP passes using route BC. The average maximum (in magnitude) LRISs are -0.43 σ a for 1 pass, -0.44 σ a for 2 pass, and 0.14 σ a for the 8 pass sample. Furthermore, these LRISs are larger than those reported previously because those earlier measurements were unable to measure the full stress tensor. Significantly, the measured stresses are inconsistent with the two-component composite model.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Thermal conductance characterization of a pressed copper rope strap between 0.13 K and 10 K

Mechanically pressing the ends of a copper braid in solid copper is an effective way of constructing solderless conductive straps for cryogenic applications. In this paper we present thermal conductance data of such a copper strap measured using the two-heater one-thermometer method. The measurements span a wide temperature range of 0.13–10 K applicable to a variety of cryogenic systems employing liquid helium, pulse tube coolers, adiabatic demagnetization refrigerators, and others. Above ≈1.5 K, the braid thermal conductivity dominates the strap conductance resulting in a near-linear dependence with temperature. The variation with temperature below ≈1.5 K is near-quadratic indicating dominance of the pressed contact conductance at the strap ends. In conclusion, electron-beam welding the braid to the strap ends is shown to be a promising solution for improving sub-Kelvin thermal conductance of the strap.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

Pressed copper and gold-plated copper contacts at low temperatures – A review of thermal contact resistance

Cryogenic systems that utilize cryocoolers with conduction cooling for attaining temperatures of 4.2 K and below routinely employ mechanically pressed components of copper to form the heat conduction path. To help with the design of such systems, the present paper introduces thermal contact resistance data of pressed copper-copper and gold-plated copper-copper contacts from nearly twenty measurement programs that span across past fifty years. Relevant theoretical models of thermal contact resistance are briefly reviewed and compared with the experimental data. Gold-plated copper contacts display reasonable trend with the models, which may serve as a design reference for such contacts. A few measurement techniques are also summarized that enable quick characterization of thermal contacts at low temperatures.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Dry-pressed lithium nickel cobalt manganese oxide (NCM) cathodes enabled by holey graphene host

There is an increasing demand for electric vehicle batteries with higher energy densities that can be manufactured with low cost utilizing environmentally friendly processes. Lithium nickel cobalt manganese oxides (NCM), such as LiNi(0.5)Co(0.2)Mr(0.3)O(2) (NCM523), are commonly used in commercial lithium ion batteries for electric vehicle applications. These cathodes are typically fabricated using environmentally hazardous, energy intensive, and time-consuming solvent-based slurry casting processes. Polymeric binders, also required for cathode preparation, add weight and can undergo parasitic reactions during battery cycling. Here we report a facile, solvent-free, binder-free, and rapid cold-press electrode fabrication process to prepare high mass loading NCM cathodes within minutes. This process is enabled by the use of holey graphene, a unique lightweight, compressible carbon nanomaterial that serves as both a binder and an electrically conductive matrix. NCM cathodes fabricated by this method are stable and exhibit good active material utilization. A significant advantage for the dry-press process is that the electrode mass loadings can be readily increased simply by adding more composite powder to the compression molding die, resulting in improved areal capacities that are attractive for applications requiring high energy per unit footprint. (C) 2020 Elsevier Ltd. All rights reserved.

25 ENERGY STORAGE↗
DOE OSTI2012

Quantitative analysis of inclusion distributions in hot pressed silicon carbide

ABSTRACT Depth of penetration measurements in hot pressed SiC have exhibited significant variability that may be influenced by microstructural defects. To obtain a better understanding regarding the role of microstructural defects under highly dynamic conditions; fragments of hot pressed SiC plates subjected to impact tests were examined. Two types of inclusion defects were identified, carbonaceous and an aluminum-iron-oxide phase. A disproportionate number of large inclusions were found on the rubble, indicating that the inclusion defects were a part of the fragmentation process. Distribution functions were plotted to compare the inclusion populations. Fragments from the superior performing sample had an inclusion population consisting of more numerous but smaller inclusions. One possible explanation for this result is that the superior sample withstood a greater stress before failure, causing a greater number of smaller inclusions to participate in fragmentation than in the weaker sample.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Microstructure and mechanical properties of NiCoCrAlYTa alloy processed by press and sintering route

Nickel-based superalloys such as NiCoCrAlY are widely used in high-temperature applications, such as gas turbine components in the energy and aerospace industries, due to their strength, high elastic modulus, and high-temperature oxidation resistance. However, the processing of these alloys is complex and costly, and the alloys are currently used as a bond coat in thermal barrier coatings. In this work, the effect of cold press and sintering processing parameters on the microstructure and mechanical properties of NiCoCrAlY alloy were studied using the powder metallurgy route as a new way to obtain NiCoCrAlYTa samples from a gas atomized prealloyed powder feedstock. High mechanical strength and adequate densification up to 98% were achieved. The most suitable compaction pressure and sintering temperature were determined for NiCoCrAlYTa alloy through microstructure characterization. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive spectroscopy microanalysis (EDS) were performed to confirm the expected γ-Ni matrix and β-NiAl phase distribution. Additionally, the results demonstrated the unexpected presence of carbides and Ni–Y-rich zones in the microstructure due to the powder metallurgy processing parameters used. Thus, microhardness, nanoindentation and uniaxial compression tests were conducted to correlate the microstructure of the alloy samples with their mechanical properties under the different studied conditions. The results show that the compaction pressure did not significantly affect the mechanical properties of the alloy samples. In this work, the compaction pressures of 400, 700 and 1000 MPa were used. The sintering temperature of 1200 °C for NiCoCrAlYTa alloy was preferred; above this temperature, the improvement in mechanical properties is not significant due to grain coarsening, whereas a lower temperature produces a decrease in mechanical properties due to high porosity and poor solid-state diffusion. - Graphical abstract: Display Omitted - Highlights: • We made NiCoCrAlYTa alloy by a conventional powder metallurgy route. • High densification and adequate strength were observed. • The presence of unexpected carbides found along γ/γ and γ/β grain boundaries was detected. • The effect of cold press and sintering processing parameters on the microstructure and mechanical properties were studied.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Transfer of microstructure pattern of CNTs onto flexible substrate using hot press technique for sensing applications

Graphical abstract: - Highlights: • Successfully transfer of microstructure patterned CNTs on PET substrate. • Demonstrate as resistor-based NH{sub 3} gas sensor in the sub-ppm range. • Excellent photodetector having instantaneous response and recovery characteristics. • An effective technique to grow and produce flexible electronic device. - Abstract: In this work, we report the successful and efficient transfer process of two- dimensional (2-D) vertically aligned carbon nanotubes (CNTs) onto polyethylene terephthalate (PET) substrate by hot pressing method with an aim to develop flexible sensor devices. Carbon nanotubes are synthesized by cold wall thermal chemical vapor deposition using patterned SiO{sub 2} substrate under low pressure. The height of the pattern of CNTs is controlled by reaction time. The entire growth and transfer process is carried out within 30 min. Strong adhesion between the nanotube and polyethylene terephthalate substrate was observed in the post-transferred case. Raman spectroscopy and scanning electron microscope (SEM) studies are used to analyze the microstructure of carbon nanotube film before and after hot pressing. This technique shows great potential for the fabrication of flexible sensing devices. We report for the first time, the application of patterned microstructure developed by this technique in the development of gas sensor and optoelectronic device. Surface resistive mode is used for detection of ammonia (NH{sub 3}) gas in the sub-ppm range. An impressive photoconducting response is also observed in the visible wavelength. The reproducibility of the sample was checked and the results indicate the possibility of use of carbon nanotube as gas sensor, photodetector, CCDs etc.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Characterization of hot-pressed von Alpen type NASICON ceramic electrolytes

The Na-ion conducting solid electrolyte NASICON is a promising solid state electrolyte (SSE) for use in Na based electrochemical systems. The effects of particle morphology and synthesis of von Alpen type NASICON via hot-pressing were investigated. Spray dried particles were shown to improve mechanical and electrochemical properties. X-ray diffraction, scanning electron microscopy, impulse excitation measurements, Vickers hardness, and impedance spectroscopy were used to correlate relationships between phase purity, microstructure, mechanical properties, and electrochemical properties. Scanning electron microscopy showed the presence of a glass phase as between 19.08% and 28.23% area percentage and a ZrO 2 phase between 0.46% and 3.51% area percentage in the hot-pressed samples. Impulse excitation showed elastic modulus varying from 83.65 to 97.65 GPa. The first values of Poisson's ratio and shear modulus of NASICON are reported as between 0.23 and 0.26 and 33.87 to 38.79 GPa, respectively. Vickers hardness and fracture toughness measurements showed Vickers hardness ranging from 4.30 to 4.68 GPa and fracture toughness ranging from 1.05 to 1.09 MPa m ½ . Impedance spectroscopy showed grain conductivities ranging from 1.023 to 1.287 mS/cm, with grain boundary resistance percentages between 73.22 and 47.5%. Total conductivities ranged from 0.292 to 0.596 mS/cm, with 0.596 mS/cm being achieved at room temperature for the spray dried powders with lower grain boundary resistance percentages.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Magnetic and magneto elastic properties of cobalt ferrite ceramic compacted through cold isostatic pressing

Nano crystalline CoFe{sub 2}O{sub 4} powder was prepared by combustion synthesis method. As synthesized powder was calcined at an appropriate condition to remove the impurities and to promote phase formation. Phase pure CoFe{sub 2}O{sub 4} powder was pressed into cylindrical rod at an applied pressure of 200 MPa using a cold isostatic pressing. Sintering of the green compact at 1350°c for 12 hrs resulted in sintered cylindrical rod with ~85% of the theoretical density. Single phase cubic spinel structure was observed in the powder x-ray diffraction pattern of the sintered pellet. Scanning electron micrographs (SEM) of the as sintered pellet revealed the microstructure to be composed of ferrite grains of average size ~4 µm. Saturation magnetization of 72 emu/g and coercivity of 355 Oe were observed for cobalt ferrite sample. The magnetostriction was measured on a circular disc (12 mm diameter and 12 mm length) with the strain gauge (350 Ω) mounted on the flat surface of the circular disc. Magnetostriciton of 180 ppm and strain derivative of 1 × 10{sup −9} m/A were observed for the sintered CoFe{sub 2}O{sub 4} sample.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Evaluation of U10Mo Fuel Plate Performance Modeling Over Hot Isostatic Press and Hydraulic Bending for MURR DDE Plates

The United States High Performance Research Reactor Program’s objective is to reduce the amount of highly enriched uranium currently implemented in research reactors. The conversion of these research reactors requires designing a monolithic U10Mo plate fuel, with the fuel plate geometry being dependent on each research reactor. The process of forming the plates includes a hot isostatic pressing (HIP) to manufacture a prototypic plate. In the case of the Missouri University Research Reactor (MURR) design demonstration element (DDE) plate manufacture, plates that have been through HIP are then curved using dies and a hydraulic press to impart the desired curvature. Both fabrication processes impart residual stresses into each fuel plate region, with the curvature of the plates taking some regions of the fuel plate up to their material yield stresses, accompanied by plastic strain. The amount of plastic strain and stress imparted onto each MURR DDE plate is determined by the radius of curvature, thickness of each region, and overall width of the fuel plates. Furthermore, this work aims to predict the yield stresses and strain using ABAQUS to simulate the proposed fabrication process of the MURR DDE plates, accompanied by discussion over the stresses and strains as to their relation to nuclear fuel performance and the impact they will have during early irradiation.

ABAQUS↗
DOE OSTI2024

Diffusion bonding of tungsten-vanadium-zirconium using vacuum hot pressing for the development of a low decay heat cladding solution for tungsten spallation targets

Tantalum has been used as cladding material for water-cooled solid tungsten targets at many leading spallation neutron production facilities thanks to its high neutron yield, manageable radiation damage behavior, and excellent corrosion/erosion resistance in radiation environments. However, from a safety hazard perspective, thermal neutron capture of tantalum in spallation environments causes a high specific decay heat in the target volume, which often becomes a limiting factor in increasing the beam power on the target. In this paper, we studied vacuum hot pressing (VHP) parameters to diffusion bond zirconium to tungsten to explore the feasibility of using zirconium alloys as an alternative cladding material to tantalum. Zirconium alloys have long been used as cladding material for early generation solid spallation targets, and nuclear fuel rods. In spallation environments zirconium has significantly lower decay heat with shorter decay time compared to tantalum. The hot isostatic pressing (HIP) of zirconium and tungsten is known to produce limited bonding quality due to the formation of the brittle ZrW2 intermetallic layer. To overcome this problem, placing a vanadium interlayer between tungsten and zirconium has been proposed by exploring parameter space in binary alloy phase diagrams. Under the VHP conditions, 860 ◦C at 70 MPa for 4 hours, Zr-V and V-W showed good diffusion bonding, which demonstrates the feasibility of a single step HIP process to make the zirconium alloy clad tungsten spallation volumes.

Lee, Yong Joong↗
DOE OSTI2015

Understanding the Role of Hot Isostatic Pressing Parameters on the Microstructural Evolution of Ti-6Al-4V and Inconel 718 Fabricated by Electron Beam Melting

In this project, Avure and ORNL evaluated the influence of hot isostatic pressing (HIP) and thermal cycling as standalone post processing techniques on the microstructure of electron beam powder bed deposited Ti-6Al-4V and Inconel 718 alloys. Electron beam powder bed deposition is an effective technology for fabricating complex net shape components that cannot be manufactured with conventional processes. However, material deposited by this technology results in columnar grain growth which is detrimental for many applications. For Ti-6Al-4V, it has been found that thermal cycling alone is not sufficient to breakdown the columnar microstructure that is typical of electron beam powder bed technology. HIP, on the other hand, has the potential to be an effective technique to break down the columnar microstructure of Ti-6Al-4V into a more equiaxed and refined β grain structure, and provide a more homogeneous microstructure compared to the thermally cycled samples. Overall, the project showed that hot isostatic pressing reduced/eliminated porosity in both Ti-6Al-4V and Inconel 718 However, based on the unique thermal cycle and the application of pressure in the HIP vessel, Ti-6Al-4V e-beam deposited microstructures were modified from columnar grain growth to equiaxed microstructures; a significant outcome to this collaboration. Inconel 718, on the other hand, shows no change in the macrostructure as a result of the current HIP cycle based on the thermal history, and would require further investigation. Though the results of HIP cycle were very good at changing the microstructure, further development in optimizing the post heat treatments and HIP cycles is required to improve mechanical properties.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Metallurgical Failure Analysis of A2 Tool Steel Die Set from High Explosive Pellet Pressing Event

On 2 April 2018, a high explosive violent reaction (HEVR) occurred during routine pressing of a 1-in -diameter cylindrical pellet of PBX 9501 high explosive. Fragments of the die set (die body and stemples) involved in the event were sent to Sigma Division for metallurgical analysis. A handheld x-ray fluorescence alloy tester confirmed the die set material to be A2 tool steel. Light optical microscopy revealed what appear to be pre-existing flaws on the inner diameter of the die body. Scanning Electron Microscopy could neither confirm nor exclude the presence of fatigue cracking in the vicinity of these potential flaws. Energy Dispersive Spectroscopy indicated the presence of a carbon-bearing residue on fracture surfaces; nitrogen-bearing residue was also found. Optical microscopy revealed that the microstructure of the stemple and inner diameter of the die body contained large stringers and non-uniform grain size; this was distinct from the relatively clean and uniform microstructure seen at the outer diameter of the die body, and also other A2 tool steel stock (pedigree unknown and with no known connection to any HE pressing hardware) that was examined for additional comparison. Rockwell hardness testing indicated the material was heat treated properly. Metallographic analysis alone could not positively identify the root cause of the event, but, coupled with accounts provided by the operator and the successful history with the particular lot of HE involved in the event, points to ward mechanical failure of the die set due to pre -existing flaw as the most likely precipitating event. Suggestions for additional analyses and future qualification techniques are discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Preparation of Four Large-format Hot Isostatically Pressed I-AgZ Waste Form Samples for Performance Testing

Hot isostatic pressing (HIP) is being considered as a process to directly convert 129 I-bearing materials to a durable radiological waste form. Zeolites, specifically silver-exchanged mordenite (AgZ), have been studied extensively as potential radioactive iodine sorbents and will contain 129 I as chemisorbed AgI, a relatively insoluble compound with a high melting point. Oak Ridge National Laboratory has conducted several recent studies on the HIP of both I–AgZ and other iodine-bearing zeolites, resulting in an inventory of samples prepared with a suite of zeolites with varied iodine incorporation methods, pressing conditions, and sizes. These samples have been made available to researchers at other national laboratories in support of test method development to assess the stability of heterogenous iodine-bearing waste forms. The work described here generated four large-format HIPed I–AgZ samples. These samples are 1.5 in. diameter and 2 in. length and contain 49 g of I–AgZ. Two samples were prepared at an iodine loading of 64 mg I/g I– AgZ, and two samples were prepared at an iodine loading of 135 mg I/g I–AgZ. These two sets of duplicate samples will be made available upon request in support of iodine waste form durability method development efforts.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Fundamental Forces, Lasting Impressions: Historical Documentation of the Sigma Press Building (TA-3-35) Volume 1

The US Department of Energy, National Nuclear Security Administration, Los Alamos Field Office (Field Office) has prepared final documentation for the resolution of adverse effects to Building 35 in Technical Area (TA) 3 at Los Alamos National Laboratory (LANL or the Laboratory). This documentation is being submitted to the New Mexico State Historic Preservation Officer (SHPO). TA-3-35, a Cold War-era press building, was determined eligible for listing in the National Register of Historic Places (Register) in the report Pressing Matters: An Evaluation of the Cold War Buildings at the Sigma Complex (LA-UR-15-28961). This report also identified Building TA-3-35 as excess property to be decontaminated, decommissioned, and demolished by the LANL Footprint Reduction Program in Fiscal Year 2016, an adverse effect requiring mitigation. The SHPO concurred with the both the eligibility determination of, and adverse impact to, Building TA-3-35 on February 29, 2016.

42 ENGINEERING↗