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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
DOE OSTI2021

Theory-guided Design of Refractory MPEAs for High-Temperature, Harsh-Service Conditions

Focusing on novel materials for harsh-service environments (oxidation, corrosion, and load), durability, higher operational temperature, and direct impact on power-generation technology, the goal was, using a quantitative theory-guided design approach integrated with high-throughput synthesis and characterization for validation, to accelerate by 50% the development of high temperature, refractory-based multi-principal element alloys (MPEAs) materials platforms (with co-designed oxidation-resistant, self-healing coatings) that demonstrate phase-stable operation with desired properties at 10-20% higher temperatures in oxidizing environments over state-ofthe- art systems (like Ni-stainless steels, i.e., Haynes 282 – used in critical gas turbine applications, and refractory TZM, i.e., molybdenum-rich Mo99.4-Ti0.5-Zr0.08-C0.02 in wt%). Notably, refractory MPEAs may achieve higher operational temperatures with superior creep strength and offer 50-100% larger thermal conductivity (140-170 W/m-K) than Ni-based systems, potentially eliminating active cooling, reducing system weight, complexity, and cost. Achieving this goal addresses DOE material challenges in energy generation and efficiency (higher-temperature operation), reduced lifecycle energy (waste-heat recovery), and accelerating materials development in support of AMO’s Strategic Plan and QTR goals. DOE’s Advanced Manufacturing Office (AMO) goal of reducing industrial energy intensity and GHG emissions is addressed by development of coated refractory MPEAs exhibiting 20%+ higher operational temperature (direct increase of Carnot efficiency), higher melting temperatures (better phase stability), superior creep strength (better lifetime with creep rate lower by factor of 10), larger (50-100%) thermal conductivity (improved cooling without active cooling), reduced complexity (single-phase alloys), self-healing coating (reliable oxidation-resistance) and cost.

36 MATERIALS SCIENCE↗
DOE OSTI2024

High Temperature Mechanical Behavior of Refractory Alloys with Digital Image Correlation

Gas turbine efficiency is typically limited by the maximum allowable temperature for components at the inlet side and in the hot gas flow. Refractory alloys and SiC/SiC ceramic-matrix composites (CMCs) are promising candidates for advancing operating temperatures beyond those of Ni-based alloys (>1200 °C). Refractory alloys are more suitable than SiC/SiC CMCs for dynamic components, due to the latter's low toughness and ductility. However, it is well known that refractory alloys suffer from poor oxidation behavior under service lifetimes and conditions, leading to embrittlement concerns. The ARPA-E ULTIMATE program has set out to combine new alloys with advanced coatings to mitigate oxidation/embrittlement effects, while increasing the mechanical performance benefits of refractory materials. Low oxygen (inert gas) or vacuum systems are needed to assess high temperature mechanical performance of developed alloys. To investigate the environmental sensitivity of candidate alloys and develop high temperature testing capabilities, four argon tensile frames were upgraded as well as a single vacuum system at Oak Ridge National Laboratory. Digital image correlation was incorporated into the vacuum frame allowing for surface strain determination and refined insight into thermomechanical response. Creep testing was performed at 1300 °C on two alloys, C-103 and MHC in vacuum and high purity argon environments. The Mo-based alloy showed less sensitivity to oxygen, indicating that testing in well-controlled argon environments may be suitable. The C-103 alloy demonstrated a stronger sensitivity to oxygen in the well-controlled argon environment, illustrating the need for the developed vacuum testing capabilities. “Small” 25 mm and “large” 76 mm MHC specimens showed comparable results in terms of strain rate during creep testing and ultimate tensile strength during tensile testing, suggesting the viability of smaller geometries that use less material of advanced developmental alloys.

Bell, Sam↗
NASA NTRS1988

Refractory lithophile elements

The abundance and distributions of refractory lithophile elements in chondritic meteorites and calcium-aluminum inclusions (CAIs) are presently noted to indicate that protoplanetary material was heated to very high temperatures. Three subsequent elemental fractionations have since been resolved: (1) that within the CAIs, indicating temperatures high enough to evaporate much of the refractory element content; (2) that of the refractory lithophile elements; and (3) that of Mg and Si, which indicates that the high temperatures were prevalent throughout the chondrite-formation region. Attention is given to models that have been proposed to explain elemental and isotopic abundances of refractory lithophile elements in chondritic material.

Larimer, John W.↗
NASA NTRS1990

Chemical compositions of refractory inclusions from the Vigarano and Leoville carbonaceous chondrites

The contents of the major and the trace elements of three refractory inclusions from Leoville and two hibonite-rich refractory inclusions and a dark clast from Vigarano were investigated using INAA technique, and the results were compared with results reported for an Allende inclusion. It was found that two out of the three refractory inclusions from Leoville and both inclusions from Vigarano have lower Na and Au contents than the coarse-grained inclusion from Allende. It is shown that the concentrations of all volatile elements in refractory inclusions in the Leoville and Vigarano meteorites tend to be either below or at the low end of their concentration ranges in Allende coarse-grained inclusions. This is considered to be due to the fact that the former were altered in parts of the solar nebula where grain-bias separation processes removed the inclusions from chemical communication with the gas at a higher temperature or after a shorter time than for the inclusions from Allende.

Mao, Xue-Ying↗
NASA NTRS1993

Isotopic and trace element characteristics of an unusual refractory inclusion from Essebi

The isotopic and chemical properties of Ca-Al-rich inclusions (CAI) provide important clues to the early solar nebula environment. While the abundances of refractory major and trace elements are similar to those expected for high temperature condensates, the variety of textural, chemical, and isotopic signatures indicate most CAI experienced complex, multi-stage histories involving repeated episodes of condensation, evaporation, and metamorphism. Evidence of multiple processes is especially apparent in an unusual refractory inclusion from Essebi (URIE) described by El Goresy et al. The melilite (mel)-rich core of URIE contains polygonal framboids of spinel (sp) and hibonite (hb) or sp and fassaite (fas) and is surrounded by a rim sequence consisting of five layers. In contrast to rims on Allende, the mineralogy of the URIE rim layers becomes increasingly refractory from the core outwards, ending in a layer of spinel-Al2O3 solid solution + Sc-rich fassaite. The chemical and mineralogical features of URIE are inconsistent with crystallization from a homogeneous melt, and El Goresy et al. proposed a multi-step history involving condensation of sp + hb and aggregation into framboids, capture of framboids by a refractory silicate melt droplet, condensation of rim layers, and alteration of mel to calcite and feldspathoid. The PANURGE ion probe was used to investigate the isotopic and trace element characteristics of URIE to develop a more complete picture of the multiple processes leading to formation and metamorphism.

Deloule, E.↗
NASA NTRS1999

Nucleation, Growth, Annealing, and Coagulation of Refractory Oxides and Metals: Recent Experimental Progress and Applications to Astrophysical Systems

Starting with cooling, refractory vapors diluted in significant quantities of H and He there are four processes that most natural systems will undergo: nucleation, growth, annealing, and coagulation. Nucleation is the processes by which the first stable refractory nuclei form in the vapor. These are the seeds onto which the remaining vapors will condense during the growth stage. Solids of any composition will try to arrange themselves into the least energetic configuration, provided that there is sufficient energy available to support such processes as diffusion and the breaking of chemical bonds. There is a significant activation energy associated with the annealing process in refractory solids due to the relatively high energy of the chemical bonds in solids. The grains formed in most cosmochemical systems are extremely small and often tightly coupled to the gas. Because of their small physical cross sections coagulation may be a very slow process unless there is another driving force involved in addition to normal Brownian motion. In what follows we will briefly cover each of these four stages for refractory oxide and metal grains, although in inverse order.

Nuth, J. A.↗
NASA NTRS2005

Performance Assessment of Refractory Concrete Used on the Space Shuttle's Launch Pad

The John F. Kennedy Space Center (KSC) maintains several facilities for launching space vehicles. During recent launches it has been observed that the refractory concrete materials that protect the steel-framed flame duct are breaking away from this base structure and are being projected at high velocities. There is significant concern that these projected pieces can strike the launch complex or space vehicle during the launch, jeopardizing the safety of the mission. A qualification program is in place to evaluate the performance of different refractory concretes and data from these tests have been used to assess the performance of the refractory concretes. However, there is significant variation in the test results, possibly making the existing qualification test program unreliable. This paper will evaluate data from past qualification tests, identify potential key performance indicators for the launch complex, and will recommend a new qualification test program that can be used to better qualify refractory concrete.

Trejo, David↗
NASA NTRS2009

Properties of Refractory Concrete in Tension and Compression

Refractory concrete on the LC-39A Flame Deflector has been damaged during multiple Space Shuttle launches (e.g. STS-124, STS-126, STS-119, and STS-125, STS-127). These events have prompted a better understanding of the system via an analytical model of the Flame Deflector assembly to include the Fondu Fyre refractory concrete. This model requires test data inputs of the refractory concrete's mechanical properties, which include stress versus strain curves in tension and compression, modulus of elasticity, and Poisson's ratio. Sections of Fondu Fyre refractory concrete removed from the LC-39A Flame Deflector were provided for this testing.

Sampson, Jeffrey↗
NASA NTRS2009

Refractory Materials for Flame Deflector Protection System Corrosion Control: Flame Deflector Protection System Life Cycle Cost Analysis Report

A 20-year life cycle cost analysis was performed to compare the operational life cycle cost, processing/turnaround timelines, and operations manpower inspection/repair/refurbishment requirements for corrosion protection of the Kennedy Space Center launch pad flame deflector associated with the existing cast-in-place materials and a newer advanced refractory ceramic material. The analysis compared the estimated costs of(1) continuing to use of the current refractory material without any changes; (2) completely reconstructing the flame trench using the current refractory material; and (3) completely reconstructing the flame trench with a new high-performance refractory material. Cost estimates were based on an analysis of the amount of damage that occurs after each launch and an estimate of the average repair cost. Alternative 3 was found to save $32M compared to alternative 1 and $17M compared to alternative 2 over a 20-year life cycle.

Calle, Luz Marina↗
DOE OSTI2022

ADDITIVE MANUFACTURING OF REFRACTORY ALLOYS

Refractory alloys are known for their high temperature capabilities and are intended for use at ultra-high temperatures above even 1200°C, which exceeds the capabilities of conventional superalloys. Additive manufacturing (AM) is an attractive alternative processing route because refractory alloys are difficult to fabricate through traditional methods; AM can form a near net-shape part with a tailored microstructure. This work seeks to evaluate the solidification behavior of refractory alloys under AM conditions and establish corresponding solidification models. Two binary alloys, Mo30Nb and Nb7.5Ta, as well as the commercial Nb alloy, C103, and one refractory high entropy alloy (RHEA), MoNbTaTi, were subjected to single track melts in a laser powder bed fusion (LPBF) machine. Each melt track was evaluated in the scanning electron microscope (SEM), which determined that some AM conditions used led to non-ideal behavior. Electron backscatter diffraction (EBSD) revealed that the Nb7.5Ta, C103, and MoNbTaTi all exhibited new grain nucleation to various extents while the Mo30Nb exhibited primarily epitaxial growth. This was found to be inconsistent with solidification models that were developed for each alloy and each set of AM conditions to predict the columnar to equiaxed transition behavior (CET) of the experimental microstructures. This disparity was largely attributed to the input parameters for the solidification model, which were developed using Thermo-Calc and SYSWELD. These input parameters include the alloy specific Gibbs-Thomson coefficient and thermophysical properties, the solute specific liquidus slopes and partitioning coefficients, as well as the process specific thermal gradients. Each input parameter was evaluated to determine the likely changes required for the modeled values to generate solidification models that better correspond to what was observed experimentally.

Miklas, Abigail↗
DOE OSTI2023

USE OF NOVEL REFRACTORY DESIGN AND INSTALLATION TECHNIQUES FOR IMPROVED ENERGY EFFICIENCY IN IRON AND STEEL AND OTHER ENERGY INTENSIVE INDUSTRIES

This work describes a US Department of Energy funded program which unites key players to develop and deploy new technologies aimed at increasing energy efficiencies while reducing their overall energy and environmental footprint. The research brings together a vertically integrated collaborative team consisting of the end user (US Steel), material producers/suppliers (Allied Mineral Products and Reno Refractories), raw material suppliers (American Metallurgical Services, Minerals Manufacturing), and research organizations (Oak Ridge National Laboratory, National Energy Technology Laboratory and University of Alabama-Birmingham) with the objective of designing and producing new refractory materials. Design and production criteria are based on novel aggregates, improved particle packing, and engineered surface textures. In addition, the recycling and use of spent refractory materials has been investigated resulting in development of a novel installation technique that utilizes additive manufacturing technology and existing refractory shotcrete technology. The combination of these new technologies will improve the energy, environmental, and economic efficiencies of the steel industry while reducing the environmental footprint. The developed technology is potentially applicable to additional energy intensive industries including cement, glass, pulp and paper, and non-ferrous metals processing.

Hemrick, James↗
DOE OSTI2024

Microstructure and Chemical Composition of Al2O3-, Cr2O3- and MgO-rich Refractories Exposed to Plastic Ashes

Plastics are widely integrated with today’s lifestyle due to their low cost, durability, lightweight, water resistance, and flexibility. However, tremendous plastic waste cause severe threats to the environment. Thus, sustainable recycling of plastic waste is critical, where plastic waste gasification technology with carbon management becomes one of the most effective recycling methods. We simulate the gasification process by exposing the Al2O3-, Cr2O3- and MgO-rich refractories to synthetic plastic ashes at 1500 ℃ for 50 h. A comprehensive study on the microstructure and chemical composition change before/after exposure is conducted using scanning electron microscopy. Meanwhile, the differences among these three refractories after exposure are revealed for quantifying the performance in plastic ashes. Discussion of the results will establish an understanding of the influence of plastic ashes on the microstructure, composition, and phase of different types of refractories, providing insights into designing new refractory materials for future recycling of plastic waste.

Fang, Xiaotian↗
DOE OSTI2025

Computational Fluid Dynamics Simulations of Glass Vitrification Refractory Coupon Tests

The Waste Treatment and Immobilization Plant (WTP) at the Hanford site is nearing the start of the Direct-Feed Low-Activity Waste (DFLAW) operations. DFLAW is destined to convert a pretreated low activity waste portion of the 56 million gallons of tank waste into a stable solid glass. In the subsequent decade completion of the high-level waste (HLW) facility is anticipated. Sustained operational missions of both LAW and HLW melter facilities are expected over multiple decades. In high-temperature glass melters, the refractory lining corrodes over time, which could potentially be an issue for longer term operations, this refractory corrosion is higher at the level of the glass-air interface due to surface tension driven flow. The glass viscosity, melt pool temperature, and glass chemical composition can impact the rate at which the refractory corrodes. This rate is important to quantify for the various waste glasses to be produced at the WTP since the integrity of the refractory should not be a limiting factor affecting the lifetime of the melter. To this end, a series of glasses representative of the first batches of waste glass produced by the WTP will be melted in small-scale crucibles with Monofrax® K-3 coupons inserted. The corrosion of the K-3 will be measured in the melt and at the meltline (or neckline). A model for the corrosion rate will be constructed and implemented into a previously developed framework for a computational fluid dynamics (CFD) model of the full-scale WTP. To assist with experimental design and validate the implementation of the model in the full-scale melter, CFD simulations of the small-scale crucible tests were performed. The bubbling that occurs in the small-scale crucible is initially validated here with a model that uses silicone oil at room temperature. The viscosity of the oil ranges from 1 to 100 Pa•s, which corresponds to operating glass pool temperatures near 1150 °C down to idling temperatures near 950 °C. The simulation results show good agreement with the bubble sizes that form during experiments. CFD modeling of the crucible setup was used to determine bubbling characteristics to match the range of near-wall velocities expected in the full-scale WTP. This study presents the initial CFD modeling results, corrosion testing plan, and some preliminary corrosion samples with an outline for the next steps for the development of the corrosion model.

Abboud, Alexander W. [Idaho National Lab]↗
DOE OSTI2018

Interface Analyses Between a Case-Hardened Ingot Casting Steel and Carbon-Containing and Carbon-Free Refractories

Corrosion tests of carbon-free and carbon-containing refractories were performed. The carbon-free crucibles corroded, whereas the carbon-containing crucibles were negligibly attacked. On them, inclusions were attached. This study investigates melt oxygen contents, interface properties, and steel compositions with their non-metallic inclusions in order to explore the inclusion formation and deposition mechanisms. The carbon-free crucibles were based on alumina, mullite, and zirconia- and titania-doped alumina (AZT). The carbon-containing (-C) ones were alumina-C and AZT-C. Furthermore, nanoscaled carbon and alumina additives (-n) were applied in an AZT-C-n material. In the crucibles, the case-hardened steel 17CrNiMo7-6 was remelted at 1580 °C. It was observed that the melt and steel oxygen contents were higher for the tests in the carbon-free crucibles. Into these crucibles, the deoxidizing alloying elements Mn and Si diffused. Reducing contents of deoxidizing elements resulted in higher steel oxygen levels and less inclusions, mainly of the inclusion group SiO 2 -core-MnS-shell (2.5 to 8 μm). These developed from smaller SiO 2 nuclei. The inclusion amount in the steel was highest after remelting in AZT-C-n for 30 minutes but decreased strongly with increasing remelting time (60 minutes) due to inclusions’ deposition on the refractory surface. The Ti from the AZT and the nanoadditives supported inclusion growth and deposition. Other inclusion groups were alumina and calcium aluminate inclusions. Their contents were high after remelting in carbon- or AZT-containing crucibles but generally decreased during remelting. On the AZT-C-n crucible, a dense layer formed from vitreous compositions including Al, Ca, Mg, Si, and Ti. To summarize, for reducing forming inclusion amounts, mullite is recommended as refractory material. For capturing formed inclusions, AZT-C-n showed a high potential.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Refractory-based thermal energy storage for industrial process heat: one-dimensional modeling, control, and optimization

The variable and weather-dependent output of wind and solar power plants present a substantial challenge for planning and operating electricity-systems, particularly in the absence of cost-effective and dispatchable energy storage technologies. This study investigates a high-temperature, electrically heated, refractory-based thermal energy storage (RTES) system that stores electrical energy as sensible heat in dense ceramic bricks over the 950–1800 °C range. The stored heat can be discharged as a controlled hot-gas stream for industrial heating, fuel substitution in high-temperature processes, or electricity generation. The main novelty is a comprehensive modelling, control, mapping, and optimization framework that integrates one-dimensional transient gas–solid heat transfer, fan-assisted discharge, bypass-flow regulation, reheating logic, fan-power evaluation, insulation-loss assessment, and genetic-algorithm-based design optimization. The model uses feedback from outlet temperature and delivered power to regulate discharge, while a two-stage genetic algorithm optimizes brick-channel geometry, gas-flow operation, and multilayer insulation thicknesses. Storage capacities below 50 MWh and discharge powers of 5–30 MW are analyzed to evaluate hold time, thermal delivery, fan-power penalty, heat loss, state-of-charge evolution, and indicative capital cost. Results demonstrate that optimized and well-insulated refractory-based thermal energy storage units can provide stable, efficient, and repeatable heat delivery over multiple discharge cycles. The generated performance and cost maps support modular refractory thermal energy storage as a practical option for large-scale integration of wind and solar generation and for high-temperature industrial process heat.

25 ENERGY STORAGE↗
DOE OSTI2025

Transferable predictions of energetic and structural properties for refractory solid solution alloys across chemical compositions

We present a data-efficient approach to train graph neural networks (GNNs) on density functional theory (DFT) data for accurate and transferable predictions of energetic and structural properties of refractory solid solution alloys in the niobium-tantalum-vanadium (Nb-Ta-V) chemical space. We start by training the GNN model only on DFT data that describes refractory binary alloys niobium-tantalum (Nb-Ta), niobium-vanadium (Nb-V), and tantalum-vanadium (Ta-V) to predict formation enthalpy and root mean squared displacement. Once trained, the GNN predictions are tested on DFT data describing refractory ternary alloys Nb-Ta-V. While, unsurprisingly, direct transferability from binary to ternary is not sufficiently accurate, augmenting the training with only 1% of the available ternary data (uniformly distributed across the entire range of chemical compositions) improves significantly the quality of the GNN predictions. For comparison, we assess the transferability in the opposite direction by training GNN models on ternary Nb-Ta-V data and making predictions on binaries Nb-Ta, Nb-V, and Ta-V, which exhibits notably higher predictive errors. The proposed methodology, which favors transferability from lower-component to higher-component alloys, offers an efficient path towards avoiding the curse of dimensionality incurred when collecting DFT data for discovery and design of multi-component disordered alloys.

Density functional theory calculations↗
DOE OSTI2018

Reducing energy consumption and carbon emissions of magnesia refractory products: A life-cycle perspective

China is the largest producer of magnesia refractory materials and products in the world, resulting in significant energy consumption and carbon emissions. This paper analyzes measures to reduce both the energy consumption and carbon emissions in the production phase and use phase, providing a theoretical basis for a sustainable magnesia refractory industry. Results show that the total carbon emissions of carbon-containing magnesia bricks produced with fused magnesia are much higher than those of other products, and the total carbon emissions of both general magnesia brick and magnesia-carbon spray are lower than those of other products. Carbon emissions of magnesia products are mainly concentrated in the production process of magnesia. Manufacturers should select materials with lower environmental impacts and emphasize saving energy and reducing carbon emissions in the magnesia production process. Through scenario analysis we found that CO 2 capture is an effective measure to reduce carbon emissions compared with just improving energy consumption. However, a robust CO 2 market does not currently exist. Policy makers should plan on integrating CO 2 capture in the magnesia industry into a regional CO 2 capture and storage development planning in the long term. In particular, magnesia production is concentrated in a single geographical area which would and thus could take advantage of significant scale effects. Finally, in the use phase, extending the service lifetime reduces carbon emissions over the product lifetime, thus users should attempt to extend the service lifetime of a furnace as a whole. However, results show that it is not advisable to add a large number of repair refractories to extend the lifetime of existing furnaces.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗