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Glass-Ceramic Material Modeling: Theory Implementation and Application.
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Controlled-Porosity Ceramic Materials for High Temperature Downhole Applications
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Femtosecond Laser Surface Processing to Create Self-Organized Micro- and Nano-Scale Features on Composite and Ceramic Materials
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A macromolecular assembly directed ceramic aerogel monolith material
Ceramic aerogels exhibit remarkable thermal insulation for energy efficient building applications, while it is indispensable to understand their nanoporous structure evolution to control their thermal regulation performance. In this study, we design and synthesize a lightweight porous silica aerogel monolithic material, and demonstrate its thermal insulation performance regulated by the morphology of porous nanostructures controlled by surfactant induced self-assembly. The micelle networks and in situ gas bubble formation guide the formation of uniform pores in the as-synthesized monolith, which shows superior thermal and acoustic insulation and robust mechanical stability with a thermal conductivity of 0.032 W m –1 K –1 , a soundproof performance improvement by 17% at a frequency of 800 Hz, and a 1.3 MPa compressive strength with a Young's modulus of 15 MPa. Lastly, these findings provide a new route to manufacture low-cost aerogel monolithic insulation materials for energy efficient building applications.
Tritium Transport Modeling at the Pore Scale in Ceramic Breeder Materials Using TMAP8
Fusion reactors depend on the blanket material to breed and release tritium at the same rate or faster than it is consumed by the fusion reaction. Cellular ceramic breeders (CCBs) are dense materials that can maintain a high tritium breeding ratio while promoting tritium release because of highly connected pores. Assessing the tritium breeding capabilities of these materials requires a combination of extensive experimental and modeling efforts. In this work, we develop and calibrate a multiphysics model of tritium transport. This novel model accounts for ceramic and pore diffusion, trapping and detrapping, and several surface reactions at the pore surface. We perform a sensitivity analysis and calibrate the model by comparing its predictions against experimental measurements of deuterium absorption. The calibrated model is then used to model tritium absorption in samples with different pore microstructures to investigate the effect of pore interconnectivity on tritium absorption. The model is part of the development of the multiscale, multiphysics framework for tritium transport [i.e., the Tritium Migration Analysis Program (TMAP8)], which is itself built on top of the finite-element multiphysics framework multiphysics object-oriented simulation environment (MOOSE). This study demonstrates some of TMAP8’s capabilities and is the first step toward assessing the tritium breeding capabilities of ceramic breeder material designs.
Porous ceramic supports for resistively heated hybrid gas sorbents
A porous sorbent ceramic product includes a three-dimensional structure having an electrically conductive ceramic material, wherein the conductive ceramic material has an open cell structure with a plurality of intra-material pores, a sorbent additive primarily present in the intra-material pores of the conductive ceramic material for adsorption of a gas, and at least two electrodes in electrical communication with the conductive ceramic material.
Transparent thermal insulation ceramic aerogel materials for solar thermal conversion
Transparent ceramic aerogel materials toward emerging energy-efficient solar thermal window technologies.
Porous ceramics for additive manufacturing, filtration, and membrane applications
In accordance with one aspect of the presently disclosed inventive concepts, a porous ceramic structure includes a three-dimensional printed structure having predefined features, where the three-dimensional structure has a geometric shape. The average length of the features may be at least 10 microns. The three-dimensional structure includes a ceramic material having an open cell structure with a plurality of pores, where the pores form continuous channels through the ceramic material from one side of the ceramic material to an opposite side of the ceramic material.
Beryllium Oxide (BeO) Handbook
Beryllium oxide (BeO) is an oxide ceramic material. BeO ceramics provide thermal conductivity second only to diamond among electrically insulating materials, dissipating nearly 300 W/mK at room temperature. This property leads to electronic applications for BeO. BeO has a thermal expansion coefficient intermediate between gallium arsenide and refractory metal composites. Its low dielectric constant (6.7) and low loss index (0.0012 at 1 MHz) permits electrical circuit performance at high frequencies. It is employed as a window material for high frequency microwave applications. BeO is very stable under oxidizing and reducing high temperature and high humidity environments, unlike nitrides which will decompose to their oxide equivalent. Similar to beryllium metal, BeO acts as a scatterer of neutrons and is used as a neutron moderator material in nuclear reactor applications. The largest use of BeO is as the raw material for the manufacture of beryllium-copper alloys, followed closely as the raw material for conversion to beryllium metal. Most of the research performed on BeO was conducted in the 1960’s and 1970’s. 75% of the references cited in this Handbook are from the time period 1960-1980. Up to 1995, there were three commercial sources of BeO: Materion Corporation, Eagle-Picher, and Ceradyne Corporation. However, since 1995 Eagle-Picher and Ceradyne no longer supply BeO commercial products. Thus, the only current commercial source of BeO materials is Materion Corporation.
Stability of ceramic matrix materials in molten hydroxide under oxidizing and reducing conditions
The degradation mechanism of ceramic matrix materials used as molten hydroxide electrolyte support for steam electrolysis cells, is not well documented. In this study, we have investigated the structural and chemical stability of non-oxide and oxide ceramics (SiC, YSZ, Li 2 ZrO 3, LiAlO 2 , and SrZrO 3 ) in the presence of molten hydroxide under oxidizing and reducing conditions with humidity levels of 3 and 85% at 550 °C. SiC, YSZ, Li 2 ZrO 3 and LiAlO 2 showed structural and chemical changes due to dissolution of the ceramic particles in the hydroxide melt followed by precipitation. The SrZrO 3 powder, on the other hand, remained both chemically and structurally stable during 500 h test under both oxidizing and reducing atmospheres. The findings of a stable ceramic matrix in molten hydroxide contribute to the enhancement of the durability and performance of intermediate temperature water electrolysis system.
Imaging grain microstructure in a model ceramic energy material with optically generated coherent acoustic phonons
Characterization of microstructure, chemistry and function of advanced energy materials remains a challenge for instrumentation science with tremendous opportunity for new discoveries. This active area of research is starting to make considerable strides with examples ranging from methodologies that employ bright X-rays, electron microscopy and optical spectroscopy. However, further development of instruments, capable of multimodal measurements, is necessary to fully reveal complex microstructure evolution in realistic environments and dynamical systems that are far from equilibrium. In this regard, laser-based instruments have a unique advantage as multiple measurement methodologies are easily combined into a single instrument using standard optics. A new pump-probe method that uses optically generated acoustic phonons is expanding standard optical characterization by providing depth resolved information. Here we report on a noteworthy extension of this pump-probe method to image grain microstructure in ceria. Rich information regarding the orientation of individual crystallites is obtained by monitoring acoustic phonon velocities and noting how the polarization of the probe beam influences the detected signal amplitude. When paired with other optical microscopies, this methodology will provide new perspectives for optical characterization of ceramic materials.
TRITIUM TRANSPORT MODELING AT THE PORE SCALE IN CERAMIC BEEDER MATERIALS USING TMAP8
Fusion reactors depend on the blanket material to breed and release tritium at the same rate or faster than it is consumed by the fusion reaction. Cellular ceramic breeders are dense materials that can maintain a high tritium breeding ratio while promoting tritium release thanks to highly connected pores. Assessing the tritium breeding capabilities of these materials requires a combination of extensive experimental and modeling efforts. In this work, we develop and calibrate a multiphysics model of tritium transport. This novel model accounts for ceramic and pore diffusion, trapping and detrapping, and several surface reactions at the pore surface. We perform a sensitivity analysis and calibrate the model by comparing its predictions against experimental measurements of deuterium absorption. The calibrated model is then used to model tritium absorption in samples with different pore microstructures to investigate the effect of pore interconnectivity on tritium absorption. The model is part of the development of the multiscale, multiphysics framework for tritium transport (i.e., the Tritium Migration Analysis Program [TMAP8]), which is itself built on top of the finite element multiphysics framework MOOSE. This study demonstrates some of TMAP8’s capabilities, and is the first step toward assessing the tritium breeding capabilities of ceramic breeder material designs.
Conductivity of cold sintered diphasic composites containing a ceramic active material and a solid-state electrolyte or carbon for all solid-state batteries
Low temperature sintering enables dense composites of ceramic active materials and conductive agents. Conductivity and microstructure of composites is characterized.
Calibration of a mesoscale tritium transport model for ceramic breeder materials in TMAP8 using experimental data
Due to the scarcity of the long-term external tritium supply, lithium-containing breeder materials are used in the blanket of fusion reactors to produce tritium faster than the deuterium-tritium fusion reaction consumes it. A cellular breeder is a promising material with higher lithium density and thermal conductivity than conventional ceramic pebbles and enhanced tritium extraction with interconnected pores. Although several experimental and modeling efforts have improved our understanding of tritium transport, the exact mechanisms governing tritium release from breeder materials are still unknown. As a result, current models cannot reliably assess the tritium breeding capabilities of cellular breeder materials. This work presents a tritium transport multiphysics model and calibrates it using experimental data of deuterium absorption and desorption from cellular breeder materials at different temperatures and pressures. This model accounts for ceramic and pore diffusion, trapping and detrapping, and several surface reactions at the pore surface. After calibrating the model and performing sensitivity analysis, we discuss pre-dominant mechanisms governing tritium release from cellular breeder materials. The model is part of the Tritium Migration Analysis Program [TMAP8], a multiscale, multiphysics framework for tritium transport based on the finite element multiphysics framework MOOSE. This study demonstrates some of TMAP8’s capabilities and provides insight into the mechanisms governing tritium transport in cellular ceramic breeder materials.
Coated fuel pellets with enhanced water and steam oxidation resistance
Disclosed herein is a method comprising coating a fissile, uranium-containing ceramic material with a water-resistant layer, the layer being non-reactive with the fissile, uranium-containing ceramic material. The coating is applied to a surface of the fissile, uranium-containing ceramic material. Also disclosed is a fuel for use in a nuclear reactor.
Observing and Modeling the Sequential Pairwise Reactions that Drive Solid‐State Ceramic Synthesis
Abstract Solid‐state synthesis from powder precursors is the primary processing route to advanced multicomponent ceramic materials. Designing reaction conditions and precursors for ceramic synthesis can be a laborious, trial‐and‐error process, as heterogeneous mixtures of precursors often evolve through a complicated series of reaction intermediates. Here, ab initio thermodynamics is used to model which pair of precursors has the most reactive interface, enabling the understanding and anticipation of which non‐equilibrium intermediates form in the early stages of a solid‐state reaction. In situ X‐ray diffraction and in situ electron microscopy are then used to observe how these initial intermediates influence phase evolution in the synthesis of the classic high‐temperature superconductor YBa 2 Cu 3 O 6+ x (YBCO). The model developed herein rationalizes how the replacement of the traditional BaCO 3 precursor with BaO 2 redirects phase evolution through a low‐temperature eutectic melt, facilitating the formation of YBCO in 30 min instead of 12+ h. Precursor selection plays an important role in tuning the thermodynamics of interfacial reactions and emerges as an important design parameter in planning kinetically favorable synthesis pathways to complex ceramic materials.
Multicomponent inorganic porous materials and methods of making the same
Provided herein is a method of preparing a porous composite ceramic material and a porous composite ceramic material made by the method of preparing.