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Materials Science and Engineering Faculty Research & Creative Works

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Full-Text Articles in Materials Science and Engineering

Impact Of Tib2 Source On The Microstructure And Properties Of Tib2–Sic–B4c Ceramics, Steven M. Smith, Suzana Filipovic, William G. Fahrenholtz, Gregory E. Hilmas, Carlo Baldisserri, Laura Silvestroni Oct 2024

Impact Of Tib2 Source On The Microstructure And Properties Of Tib2–Sic–B4c Ceramics, Steven M. Smith, Suzana Filipovic, William G. Fahrenholtz, Gregory E. Hilmas, Carlo Baldisserri, Laura Silvestroni

Materials Science and Engineering Faculty Research & Creative Works

To date, the thermal and electrical properties of three-phase ceramics containing a boride phase, silicon carbide, and boron carbide have not been studied in detail. Further, the effect of the source of the boride powder has also not been investigated. This study produced three-phase ceramics containing titanium diboride, silicon carbide, and boron carbide using three different TiB2 sources: commercial powder, TiB2 synthesized by boro/carbothermal reduction, or (Ti,Cr)B2 synthesized by boro/carbothermal reduction to address the effect of the TiB2 source. Ceramics containing synthesized TiB2 or (Ti,Cr)B2 reached >99% relative density, while the ceramic produced from …

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Development Of Robust Steel Alloys For Laser-Directed Energy Deposition Via Analysis Of Mechanical Property Sensitivities †, Jonathan Kelley, Joseph W. Newkirk, Laura N. Bartlett, Sriram Praneeth Isanaka, Todd Sparks, Saeid Alipour, Frank Liou Oct 2024

Development Of Robust Steel Alloys For Laser-Directed Energy Deposition Via Analysis Of Mechanical Property Sensitivities †, Jonathan Kelley, Joseph W. Newkirk, Laura N. Bartlett, Sriram Praneeth Isanaka, Todd Sparks, Saeid Alipour, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

To ensure consistent performance of additively manufactured metal parts, it is advantageous to identify alloys that are robust to process variations. This paper investigates the effect of steel alloy composition on mechanical property robustness in laser-directed energy deposition (L-DED). In situ blending of ultra-high-strength low-alloy steel (UHSLA) and pure iron powders produced 10 compositions containing 10–100 wt.% UHSLA. Samples were deposited using a novel configuration that enabled rapid collection of hardness data. The Vickers hardness sensitivity of each alloy was evaluated with respect to laser power and interlayer delay time. Yield strength (YS) and ultimate tensile strength (UTS) sensitivities of …

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Response Of ¹¹B Enriched Zrb2 Ultra-High Temperature Ceramic To Neutron Irradiation At Elevated Temperatures, Yan Ru Lin, Takaaki Koyanagi, David J. Sprouster, Christian M. Petrie, William Fahrenholtz, Greg Hilmas, Yutai Katoh Sep 2024

Response Of ¹¹B Enriched Zrb2 Ultra-High Temperature Ceramic To Neutron Irradiation At Elevated Temperatures, Yan Ru Lin, Takaaki Koyanagi, David J. Sprouster, Christian M. Petrie, William Fahrenholtz, Greg Hilmas, Yutai Katoh

Materials Science and Engineering Faculty Research & Creative Works

ZrB2, an ultra-high temperature ceramic (UHTC) is being considered for use in fusion reactor first-wall structures, yet its response to irradiation remains poorly understood. This study employed scanning/transmission electron microscopy (S/TEM), synchrotron X-ray diffraction (XRD), finite element calculations, and thermal property measurements to thoroughly investigate the neutron-irradiation effects on 11B-enriched ZrB2. Neutron irradiations were conducted at 220 °C and 620 °C, with a neutron fluence of 2.2 x 1025 neutron/m2 (energy > 0.1 MeV), resulting in 3.9 dpa and 4200 appm He. The study revealed the unusual prevalence of prism loops and a > c anisotropic lattice …

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Study Of The Structure Of Zn And Na Borophosphate Glasses Using X-Ray And Neutron Scattering Techniques, Uwe Hoppe, Parker T. Freudenberger, Richard K. Brow, Jozef Bednarčik, Alex C. Hannon Sep 2024

Study Of The Structure Of Zn And Na Borophosphate Glasses Using X-Ray And Neutron Scattering Techniques, Uwe Hoppe, Parker T. Freudenberger, Richard K. Brow, Jozef Bednarčik, Alex C. Hannon

Materials Science and Engineering Faculty Research & Creative Works

The atomic structures of Zn and Na borophosphate glasses were studied using X-ray and neutron scattering techniques. Peaks assigned to the B−O, P−O, and O−O distances confirm that only BO4 units co-exist with the PO4 tetrahedra. The Zn−O and Na−O coordination numbers are found to be a little larger than four. The narrowest peaks of the Zn−O first-neighbor distances exist for the glasses along a line connecting the Zn (PO3)2 and BPO4 compositions (50 mol% P2O5), which is explained by networks of ZnO4, BO4, and PO …

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Microstructural Evolution In A Precipitate-Hardened (Fe0.3ni0.3mn0.3cr0.1)94ti2al4 Multi-Principal Element Alloy During High-Pressure Torsion, Matthew Luebbe, Jiaqi Duan, Peipei Cao, Zhaoping Lu, Rinat K. Islamgaliev, Ruslan Z. Valiev, Yuzi Liu, Haiming Wen Jul 2024

Microstructural Evolution In A Precipitate-Hardened (Fe0.3ni0.3mn0.3cr0.1)94ti2al4 Multi-Principal Element Alloy During High-Pressure Torsion, Matthew Luebbe, Jiaqi Duan, Peipei Cao, Zhaoping Lu, Rinat K. Islamgaliev, Ruslan Z. Valiev, Yuzi Liu, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Multi-principal element alloys demonstrate high strength, thermal stability, and irradiation resistance, making them excellent candidate materials for applications in nuclear reactors and other harsh environments. Some studies have examined the use of high-pressure torsion to strengthen MPEAs through grain size reduction and strain hardening. However, no studies have investigated the effect of HPT on secondary phases (precipitates) within an MPEA. Two alloys, (Fe0.3Ni0.3Mn0.3Cr0.1)94Ti2Al4 containing Ni(Ti, Al) B2 phase, and CrFe σ phase, and single-phase Fe0.3Ni0.3Mn0.3Cr0.1, were fabricated by casting …

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New Generation Graphenes In Cement-Based Materials: Production, Property Enhancement, And Life Cycle Analysis, Sahil Surehali, Sayee Srikarah Volaity, Aswathy Simon, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath Jun 2024

New Generation Graphenes In Cement-Based Materials: Production, Property Enhancement, And Life Cycle Analysis, Sahil Surehali, Sayee Srikarah Volaity, Aswathy Simon, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Several studies have explored the use of graphene to improve the properties of cement-based materials. However, most commercially available graphenes are expensive, not amenable to mass production, and have high embodied energy and emissions, making their use in concrete less attractive, despite the beneficial mechanical property attributes. This paper discusses the use of two novel graphene types, fractal graphene (FG) and reactive graphene (RG), obtained through a cost-effective and scalable detonation synthesis, in cement-based materials. FG and RG are sheets containing 6-10 layers, with lateral dimensions of 20-50 nm and a z-axis thickness of RG, when added at very small …

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Atom Probe Tomography Of Segregation At Grain Boundaries And Gas Bubbles In Neutron Irradiated U-10 Wt% Mo Fuel, Maalavan Arivu, Andrew Hoffman, Mukesh Bachhav, Assel Aitkaliyeva, Yaqiao Wu, Brandon Miller, Dennis Keiser, Jian Gan, Haiming Wen Jun 2024

Atom Probe Tomography Of Segregation At Grain Boundaries And Gas Bubbles In Neutron Irradiated U-10 Wt% Mo Fuel, Maalavan Arivu, Andrew Hoffman, Mukesh Bachhav, Assel Aitkaliyeva, Yaqiao Wu, Brandon Miller, Dennis Keiser, Jian Gan, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

During Neutron Irradiation to Fission Densities > 5.2 X 1021 Fiss/cm3, Xe Agglomerates Forming Gas Bubbles of Varying Size within the U-Mo Fuel Matrix. Herein, Segregation of Fission Products to Xe Bubbles and Grain Boundaries (GB) Were Studied using Atom Probe Tomography (APT). Segregation Behavior Was Found to Vary among GBs, Small Bubbles (<10 >Nm), and Larger Bubbles (>10 Nm). Solid Fission Products Were Enriched at GBs and Larger Bubbles, But Not at Small Bubbles. a Denuded Zone Was Identified Adjacent to a > 10 Nm Xe Gas Bubble and a GB.

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Quasi-Static And Dynamic Deformation Of Aluminum Matrix Composites Reinforced By Core-Shell Al35ti15cu10mn20cr20 High-Entropy Alloy Particulates, Dezhi Zhu, Tingting Chen, Xiaoqiang Jin, Haiming Wen, Zhiqiang Fu, Shengguan Qu May 2024

Quasi-Static And Dynamic Deformation Of Aluminum Matrix Composites Reinforced By Core-Shell Al35ti15cu10mn20cr20 High-Entropy Alloy Particulates, Dezhi Zhu, Tingting Chen, Xiaoqiang Jin, Haiming Wen, Zhiqiang Fu, Shengguan Qu

Materials Science and Engineering Faculty Research & Creative Works

Core-Shell Structured Particles Are Potential Reinforcement Agents For Metal Matrix Composites. In This Work, Aluminum Matrix Composites Reinforced With Core-Shell Structured Al35Ti15Cu10Mn20Cr20 High-Entropy Alloy (HEA) Particles Were Fabricated By Spark Plasma Sintering (SPS) And High-Temperature Diffusion Post-Treatment. Dynamic Compression Behavior And Adiabatic Shear Failure Mechanism In The Composites Were Investigated By Split Hopkinson Pressure Bar (SHPB), Scanning Electron Microscopy And Transmission Electron Microscopy. Results Showed That The Shell Thickness Of The Core-Shell Particles Ranged From 0.4 To 1.6 Μm, Which Were Formed By Thermal Diffusion Between HEA Core And Aluminum Alloy. The 30 Vol% (Al35Ti15Cu10Mn20Cr20)p/2024Al Composite Showed A High Compressive …

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Adipose Stem Cell Response To Borophosphate Bioactive Glass, Nada A. Abokefa, Bradley A. Bromet, Rebekah L. Blatt, Makenna S. Pickett, Richard K. Brow, Julie A. Semon May 2024

Adipose Stem Cell Response To Borophosphate Bioactive Glass, Nada A. Abokefa, Bradley A. Bromet, Rebekah L. Blatt, Makenna S. Pickett, Richard K. Brow, Julie A. Semon

Materials Science and Engineering Faculty Research & Creative Works

Silicate and Borate Bioactive Glasses Have Been Reported to Create Alkaline Conditions by Rapidly Releasing Ions When Reacting in Aqueous Solution. at Certain Levels, This Alkaline Solution Can Negatively Affect Cell Viability. Adding Phosphate Ions to the Glass Composition Can Control the Degradation Rate of Bioactive Glasses and Create a Neutral PH Environment. This Study Evaluated a Series of Boro phosphate Bioactive Glasses (BPBGs) with Nominal Molar Compositions 16Na2O-24CaO-XB2O3-(60-X) P2O5, Where X = 0, 40, or 60. the Phosphate (X0) Glass (PBG) Produced an Acidic Solution When Dissolved …

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Hardness Of Single Phase High Entropy Carbide Ceramics With Different Compositions, Paul M. Brune, Gregory E. Hilmas, William G. Fahrenholtz, Jeremy Lee Watts, Caillin J. Ryan, Chris M. Desalle, Douglas E. Wolfe, Stefano Curtarolo Apr 2024

Hardness Of Single Phase High Entropy Carbide Ceramics With Different Compositions, Paul M. Brune, Gregory E. Hilmas, William G. Fahrenholtz, Jeremy Lee Watts, Caillin J. Ryan, Chris M. Desalle, Douglas E. Wolfe, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Five High Entropy Carbide Ceramics, (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C, (Cr0.2,Hf0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Mo0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Ta0.2,Ti0.2,W0.2,Zr0.2)C, and (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C, Were Synthesized by Carbothermal Reduction of Oxides and Direct Current Sintering. the Five High Entropy Carbide Ceramics Were Determined to Be Nominally Phase-Pure with Relative Densities of More Than 98.9% and Mean Grain Sizes of Less Than 5 Μm. Average Vickers Hardness Values Ranged from 19.2 ± 0.4 GPa for (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C at a Load of 2 Kgf to 43.5 ± 0.4 GPa for (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C at a Load of 0.05 Kgf. Hardness Generally Increased with Increasing the Valence Electron Concentration and Strain as Measured by the Williamson-Hall Analysis. However, Neither …

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Application Of The Immobilized Low-Activity Waste Glass Corrosion Model To The Static Dissolution Of 24 Statistically-Designed Alkali-Borosilicate Waste Glasses, Sebastien N. Kerisit, James J. Neeway, Charmayne E. Lonergan, Benjamin Parruzot, Jarrod V. Crum, Richard C. Daniel, Gary L. Smith, R. Matthew Asmussen Apr 2024

Application Of The Immobilized Low-Activity Waste Glass Corrosion Model To The Static Dissolution Of 24 Statistically-Designed Alkali-Borosilicate Waste Glasses, Sebastien N. Kerisit, James J. Neeway, Charmayne E. Lonergan, Benjamin Parruzot, Jarrod V. Crum, Richard C. Daniel, Gary L. Smith, R. Matthew Asmussen

Materials Science and Engineering Faculty Research & Creative Works

Glass corrosion models that capture the complex mechanisms of the glass-water reaction enable the prediction of nuclear waste glass durability in disposal scenarios. Parameterization of such models is challenging because of the need to capture changes in corrosion behavior with time, reaction conditions, and glass composition. Here, we describe and employ the ILAW (immobilized low-activity waste) glass corrosion model (IGCM) in geochemical simulations of static dissolution tests, at two temperatures (40 °C and 90 °C), for a matrix of 24 enhanced low-activity waste (eLAW) glasses statistically designed to cover a processable composition space defined by 8 major glass components (Al …

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Decoding Crystallization Behavior Of Aluminoborosilicate Glasses: From Structural Descriptors To Quantitative Structure – Property Relationship (Qspr) Based Predictive Models, Yingcheng Zhang, Marco Bertani, Alfonso Pedone, Randall E. Youngman, Gregory Tricot, Aditya Kumar, Ashutosh Goel Apr 2024

Decoding Crystallization Behavior Of Aluminoborosilicate Glasses: From Structural Descriptors To Quantitative Structure – Property Relationship (Qspr) Based Predictive Models, Yingcheng Zhang, Marco Bertani, Alfonso Pedone, Randall E. Youngman, Gregory Tricot, Aditya Kumar, Ashutosh Goel

Materials Science and Engineering Faculty Research & Creative Works

Successful decoding of structural descriptors controlling the crystallization in multicomponent functional glasses can pave the way for the transition from the trial-and-error approach and empirical modeling for glass/glass-ceramic composition design toward more rational and scientifically rigorous Quantitative Structure-Property Relationship (QSPR) based models. However, due to the compositional and structural complexity of multicomponent glasses and the longer time and length scales associated with nucleation, the development and validation of QSPR models are still in it's infancy. The work presented in the article is an attempt to leap forward in this pursuit by combining the strengths of experimental and computational materials science …

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Effect Of The Filler Morphology On The Crystallization Behavior And Dielectric Properties Of The Polyvinylidene Fluoride-Based Composite, Suzana Filipović, Nina Obradović, Cole Corlett, William G. Fahrenholtz, Martin Rosenschon, Ekkehard Füglein, Radovan Dojčilović, Dragana Tošić, Jovana Petrović, Antonije Đorđević, Branislav Vlahović, Vladimir B. Pavlović Mar 2024

Effect Of The Filler Morphology On The Crystallization Behavior And Dielectric Properties Of The Polyvinylidene Fluoride-Based Composite, Suzana Filipović, Nina Obradović, Cole Corlett, William G. Fahrenholtz, Martin Rosenschon, Ekkehard Füglein, Radovan Dojčilović, Dragana Tošić, Jovana Petrović, Antonije Đorđević, Branislav Vlahović, Vladimir B. Pavlović

Materials Science and Engineering Faculty Research & Creative Works

Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt.% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was …

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A Phenomenological Thermodynamic Energy Density Function For Ferroelectric Wurtzite Al1−Xscxn Single Crystals, Yijia Gu, Andrew C. Meng, Aiden Ross, Long Qing Chen Mar 2024

A Phenomenological Thermodynamic Energy Density Function For Ferroelectric Wurtzite Al1−Xscxn Single Crystals, Yijia Gu, Andrew C. Meng, Aiden Ross, Long Qing Chen

Materials Science and Engineering Faculty Research & Creative Works

A Landau-Devonshire thermodynamic energy density function for ferroelectric wurtzite aluminum scandium nitride (Al1−xScxN) solid solution is developed. It is parametrized using available experimental and theoretical data, enabling the accurate reproduction of composition-dependent ferroelectric properties, such as spontaneous polarization, dielectric permittivity, and piezoelectric constants, for both bulk and thin films. The maximum concentration of Sc for the wurtzite structure to remain ferroelectric is found to be 61 at. %. A detailed analysis of Al1−xScxN thin films reveals that the ferroelectric phase transition and properties are insensitive to substrate strain. This study lays the foundation for quantitative modeling of novel ferroelectric wurtzite …

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Dielectric Properties Of Polycrystalline And Single-Crystal Magnesium Oxide At High Temperatures, Alan Devoe, Hung Trinh, Fatih Dogan Mar 2024

Dielectric Properties Of Polycrystalline And Single-Crystal Magnesium Oxide At High Temperatures, Alan Devoe, Hung Trinh, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

The electrical properties of high-purity magnesium oxide (MgO) samples sintered between 1500 and 1650°C were investigated up to 800°C. Dielectric constant, loss tangent and electrical conductivity were measured between 25 and 800°C. Optimum electrical properties were obtained for the sample sintered at 1600°C. The impurities in polycrystalline and single crystal MgO were discussed to understand their effect on electrical properties and the role of grain boundaries. Higher dielectric losses of polycrystalline samples as compared to the single crystal MgO were attributed to the presence of grain boundaries. MgO could be a useful dielectric material for capacitor applications up to 600°C.

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A Priori Procedure To Establish Spinodal Decomposition In Alloys, Simon Divilov, Hagen Eckert, Cormac Toher, Rico Friedrich, Adam C. Zettel, Donald W. Brenner, William G. Fahrenholtz, Douglas E. Wolfe, Eva Zurek, Jon Paul Maria, Nico Hotz, Xiomara Campilongo, Stefano Curtarolo Mar 2024

A Priori Procedure To Establish Spinodal Decomposition In Alloys, Simon Divilov, Hagen Eckert, Cormac Toher, Rico Friedrich, Adam C. Zettel, Donald W. Brenner, William G. Fahrenholtz, Douglas E. Wolfe, Eva Zurek, Jon Paul Maria, Nico Hotz, Xiomara Campilongo, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Spinodal decomposition can improve a number of essential properties in materials, especially hardness. Yet, the theoretical prediction of the onset of this phenomenon (e.g., temperature) and its microstructure (e.g., wavelength) often requires input parameters coming from costly and time-consuming experimental efforts, hindering rational materials optimization. Here, we present a procedure where such parameters are not derived from experiments. First, we calculate the spinodal temperature by modeling nucleation in the solid solution while approaching the spinode boundary. Then, we compute the spinodal wavelength self-consistently using a few reasonable approximations. Our results show remarkable agreement with experiments and, for NiRh, the calculated …

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The Thermophysical Properties Of Tco2, Hong Zhong, Jason Lonergan, John S. Mccloy, Scott P. Beckman Mar 2024

The Thermophysical Properties Of Tco2, Hong Zhong, Jason Lonergan, John S. Mccloy, Scott P. Beckman

Materials Science and Engineering Faculty Research & Creative Works

Technetium-99 Is A Highly Radioactive Isotope With A Long Half-Life That Is Common In Nuclear Waste. It Volatizes At A Low Temperature, Which Poses A Significant Challenge To The Clean-Up And Containment Processes. Due To Difficulties In Purifying Technetium Compounds, Their Thermophysical Properties Have Not Been Measured Or Calculated. Here, First Principle Methods Are Used Along With The Quasi Quasi-Harmonic Harmonic Approximation To Compute The Debye Temperature, Volumetric Thermal Expansion Coefficient, Bulk Modulus, And Heat Capacity Of Rutile TcO2 For Temperatures Ranging From 0 To 1500 K And Applied Pressures Ranging From 0 To 255 GPa. The Computed Atomic Structures …

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Fly Ash Coated With Alumina Sol For Improving Strength And Thermal Insulation Of Mullite Porous Ceramics, Minghui Li, Peilin Li, Qingqing Gao, Saisai Li, Ruoyu Chen, Haiming Wen, Canhua Li Feb 2024

Fly Ash Coated With Alumina Sol For Improving Strength And Thermal Insulation Of Mullite Porous Ceramics, Minghui Li, Peilin Li, Qingqing Gao, Saisai Li, Ruoyu Chen, Haiming Wen, Canhua Li

Materials Science and Engineering Faculty Research & Creative Works

The manufacturing of mullite porous ceramics with high strength and low thermal conductivity was achieved through foam gel-casting processes using fly ash coated with alumina sol layers. This research aimed to investigate the effect of alumina sol concentration on foaming slurry rheology, as well as the influence of alumina sol coating layers on the microstructure, phase compositions and properties of the resulting mullite porous ceramics. Increasing the alumina sol concentration from 5 to 20 wt% improved both the viscosity and thixotropy of the foaming slurries while enhanced the shear thinning behavior. Porous ceramics prepared with fly ash coated with alumina …

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Dielectric Properties Of Polycrystalline And Single Crystal (100) Strontium Titanate From 4 To 295 K, Hung Trinh, Alan Devoe, Fatih Dogan Jan 2024

Dielectric Properties Of Polycrystalline And Single Crystal (100) Strontium Titanate From 4 To 295 K, Hung Trinh, Alan Devoe, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

The dielectric properties of single crystal and polycrystalline SrTiO3 (ST) were investigated from 295 to 4 K. Relative permittivity (εr) and loss tangent (tan(δ)) were measured systematically as a function of direct current (DC) voltage (0 V/cm to 800 V/cm), frequency (100 Hz to 1 MHz), and temperature (295 K to 4 K) for type (100) single crystal SrTiO3 (SC-ST) and for polycrystalline SrTiO3 (PC-ST). Calculated equivalent series resistance (ESR) data are also reported. Overall, the permittivity of ST showed a dependence on temperature, DC voltage, and frequency. Dependences on voltage and frequency were only observed at …

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Hanford Low-Activity Waste Vitrification: A Review, José Marcial, Brian J. Riley, Albert A. Kruger, Charmayne E. Lonergan, John D. Vienna Jan 2024

Hanford Low-Activity Waste Vitrification: A Review, José Marcial, Brian J. Riley, Albert A. Kruger, Charmayne E. Lonergan, John D. Vienna

Materials Science and Engineering Faculty Research & Creative Works

This Paper Summarizes the Vast Body of Literature (Over 200 Documents) Related to Vitrification of the Low-Activity Waste (LAW) Fraction of the Hanford Tank Wastes. Details Are Provided on the Origins of the Hanford Tank Wastes that Resulted from Nuclear Operations Conducted between 1944 and 1989 to Support Nuclear Weapons Production. Waste Treatment Processes Are Described, Including the Baseline Process to Separate the Tank Waste into LAW and High-Level Waste Fractions, and the LAW Vitrification Facility Being Started at Hanford. Significant Focus is Placed on the Glass Composition Development and the Property-Composition Relationships for Hanford LAW Glasses. Glass Disposal Plans …

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High-Temperature Oxidation Behavior Of High Entropy Carbide (Tanbtiv)C In Atmospheres With Different Oxygen Contents, Ruoyu Chen, Hongbin An, Jie Zhan, Saisai Li, Aiqin Mao, Haiming Wen Jan 2024

High-Temperature Oxidation Behavior Of High Entropy Carbide (Tanbtiv)C In Atmospheres With Different Oxygen Contents, Ruoyu Chen, Hongbin An, Jie Zhan, Saisai Li, Aiqin Mao, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

A high entropy carbide (TaNbTiV)C was fabricated via spark plasma sintering of high entropy powders that were prepared using a molten salt method. The as-fabricated high entropy carbide was then investigated for its high-temperature oxidation behavior at 850 °C, under atmospheres with three different oxygen contents (20 vol%, 40 vol%, and 60 vol%). After the high-temperature oxidation process, the main phases observed in all the specimens were incompletely oxidized phase (NbxTi1-x)CyO2-y and oxides (Nb0.5Ta0.5)2O5, TiO2, and Nb2O5. Importantly, the …

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Synergistic Hardening In A Dual Phase High-Entropy (Hf,Nb,Ta,Ti,Zr)C–(Hf,Nb,Ta,Ti,Zr)B2 Ultra-High Temperature Ceramic, Rubia Hassan, William G. Fahrenholtz, Gregory E. Hilmas, Stefano Curtarolo Jan 2024

Synergistic Hardening In A Dual Phase High-Entropy (Hf,Nb,Ta,Ti,Zr)C–(Hf,Nb,Ta,Ti,Zr)B2 Ultra-High Temperature Ceramic, Rubia Hassan, William G. Fahrenholtz, Gregory E. Hilmas, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

A dual phase high-entropy (Hf,Nb,Ta,Ti,Zr)C–(Hf,Nb,Ta,Ti,Zr)B2 ultra-high temperature ceramic was synthesized using a single step boro-carbothermal reduction route. The synthesized powder was densified by spark plasma sintering at 2000°C, resulting in complete solid solution formation and a relative density of ≈99%. The dual phase ceramic was 43 vol% high-entropy carbide and 57 vol% high-entropy boride. The grain sizes were 0.85 ± 0.34 µm for the carbide and 0.87 ± 0.33 µm for the boride with minimal residual oxide (0.2 vol%) detected in the microstructure. The resulting composition had a higher microhardness than the individual boride and carbide ceramics across the range …

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Cf/Sic Ceramic Matrix Composites With Extraordinary Thermomechanical Properties Up To 2000 °C, Min Sung Park, Jian Gu, Heesoo Lee, Sea Hoon Lee, Lun Feng, William Fahrenholtz Jan 2024

Cf/Sic Ceramic Matrix Composites With Extraordinary Thermomechanical Properties Up To 2000 °C, Min Sung Park, Jian Gu, Heesoo Lee, Sea Hoon Lee, Lun Feng, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The thermomechanical properties of carbon fiber reinforced silicon carbide ceramic matrix composites (Cf/SiC CMCs) were studied up to 2000 °C using high temperature in situ flexural testing in argon. The CMC specimens were fabricated using an ultrahigh concentration (66 vol%) aqueous slurry containing nano-sized silicon carbide powder. The SiC powder compacts were obtained by drying the slurry and were densified using the precursor impregnation and pyrolysis (PIP) method with field assisted sintering technology/spark plasma sintering (FAST/SPS). The high relative density of the SiC green body (77.6%) enabled densification within 2.5 days using four PIP cycles. In contrast, conventional PIP processes …

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Phosphate-Based Dechlorination Of Electrorefiner Salt Waste Using A Phosphoric Acid Precursor, Paige Murray, Harmony Werth, Sean Sullivan, Brian J. Riley, Michael Simpson, Charmayne E. Lonergan, Krista Carlson Jan 2024

Phosphate-Based Dechlorination Of Electrorefiner Salt Waste Using A Phosphoric Acid Precursor, Paige Murray, Harmony Werth, Sean Sullivan, Brian J. Riley, Michael Simpson, Charmayne E. Lonergan, Krista Carlson

Materials Science and Engineering Faculty Research & Creative Works

Electrochemical processing of spent nuclear fuel in molten chloride salts results in radioactive salt waste. Chlorine removal from the salt has been identified as an effective and efficient first step in the management of high-level waste. In this work, a simple salt was dechlorinated with a phosphoric acid phosphate precursor, resulting in a glassy dechlorinated product. The dechlorination efficacy was evaluated in air and argon environments. This work serves as an initial step to advance the technological readiness level of h3po4-based dechlorination step toward implementation of iron phosphate waste forms to immobilize electrochemical fuel reprocessing salt waste streams.

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Thermal And Electrical Properties Of Single-Phase High Entropy Carbide Ceramics, Paul M. Brune, Gregory E. Hilmas, William G. Fahrenholtz, Jeremy Lee Watts, Stefano Curtarolo Jan 2024

Thermal And Electrical Properties Of Single-Phase High Entropy Carbide Ceramics, Paul M. Brune, Gregory E. Hilmas, William G. Fahrenholtz, Jeremy Lee Watts, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Thermal and Electrical Properties Were Investigated for Five Nominally Phase-Pure High Entropy Carbide Ceramics. the Compositions (Hf0.2Nb0.2Ta0.2Ti0.2Zr0.2)C, (Cr0.2Hf0.2Ta0.2Ti0.2Zr0.2)C, (Hf0.2Mo0.2Ta0.2Ti0.2Zr0.2)C, (Hf0.2Ta0.2Ti0.2W0.2Zr0.2)C, and (Hf0.2Mo0.2Ti0.2W0.2Zr0.2)C Were Synthesized by Carbothermal Reduction of Oxides. the Thermal Diffusivity and Heat Capacity Were Measured from Room Temperature to 1800°C. the Room Temperature Thermal Conductivity Ranged from 5.1 W/mK for (Hf0.2Mo0.2Ti0.2W0.2Zr0.2)C to 9.0 W/mK for (Cr0.2Hf0.2Ta0.2Ti0.2Zr0.2)C. the Thermal Conductivity Increased over the Temperature Range with Maximum Conductivities of 19.6 W/mK Measured for (Hf0.2Mo0.2Ta0.2Ti0.2Zr0.2)C to 29.7 W/mK for (Cr0.2Hf0.2Ta0.2Ti0.2Zr0.2)C at 1800°C. the Electron Contribution to Thermal Conductivity Calculated from Measured Electrical Resistivity Varied from 41% to 52% of the …

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Pressureless Sintering And Properties Of Additively Manufactured Zrb2–Sic, Marharyta Lakusta, Nicholas M. Timme, Jeremy L. Watts, William G. Fahrenholtz, Gregory E. Hilmas, David W. Lipke Jan 2024

Pressureless Sintering And Properties Of Additively Manufactured Zrb2–Sic, Marharyta Lakusta, Nicholas M. Timme, Jeremy L. Watts, William G. Fahrenholtz, Gregory E. Hilmas, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Densification behavior, grain growth kinetics, mechanical and thermal properties of pressurelessly sintered zirconium diboride–silicon carbide (ZrB2–SiC) fabricated by extrusion of high solids loading pastes have been studied. The effects of sintering temperature (1600–2300°C), heating rate during constant heating rate sintering (10–50°C/min), and time during isothermal sintering (3–24 h) on density and grain size were examined. The apparent activation energy for densification was determined to be 940 ± 90 kJ/mol, suggesting lattice diffusion as the dominant sintering mechanism. Grain growth of both ZrB2 and SiC followed a normal grain growth power law with grain growth exponent n = 2 indicating diffusion-controlled …

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A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis, Jacob N. Ortega, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daniel Stutts, Daoru Han Jan 2024

A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis, Jacob N. Ortega, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daniel Stutts, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

This paper presents a concept of producing aluminum in-situ on the lunar surface, namely, the Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE) method developed at Missouri University of Science and Technology. This paper aims to demonstrate the use of electro-deoxidation to reduce aluminum oxide (i.e., alumina) into aluminum and oxygen gas via electrolysis in a molten salt bath for the production of aluminum on the Moon. It is shown that with a steady supply of hydrogen chloride, this in-situ resource utilization (ISRU) method could supply several necessary materials consumed in the electro-deoxidation process except hydrogen chloride to produce …

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Spark Plasma Sintering Of Magnesium Titanate Ceramics, Suzana Filipović, Nina Obradović, William G. Fahrenholtz, Steven Smith, Miljana Mirković, Adriana Peleš Tadić, Jovana Petrović, Antonije Đorđević Jan 2024

Spark Plasma Sintering Of Magnesium Titanate Ceramics, Suzana Filipović, Nina Obradović, William G. Fahrenholtz, Steven Smith, Miljana Mirković, Adriana Peleš Tadić, Jovana Petrović, Antonije Đorđević

Materials Science and Engineering Faculty Research & Creative Works

Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was …

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A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis, Jacob N. Ortega, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daniel Stutts, Daoru Han Jan 2024

A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis, Jacob N. Ortega, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daniel Stutts, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

This paper presents a concept of producing aluminum in-situ on the lunar surface, namely, the Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE) method developed at Missouri University of Science and Technology. This paper aims to demonstrate the use of electro-deoxidation to reduce aluminum oxide (i.e., alumina) into aluminum and oxygen gas via electrolysis in a molten salt bath for the production of aluminum on the Moon. It is shown that with a steady supply of hydrogen chloride, this in-situ resource utilization (ISRU) method could supply several necessary materials consumed in the electro-deoxidation process except hydrogen chloride to produce …

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Sic Addition To A Dual Phase High Entropy Ultra-High Temperature Ceramic, Rubia Hassan, William G. Fahrenholtz, Kantesh Balani, Gregory E. Hilmas, Jeremy Watts Jan 2024

Sic Addition To A Dual Phase High Entropy Ultra-High Temperature Ceramic, Rubia Hassan, William G. Fahrenholtz, Kantesh Balani, Gregory E. Hilmas, Jeremy Watts

Materials Science and Engineering Faculty Research & Creative Works

Dual phase (Hf,Ta,Ti,W,Zr)B2-(Hf,Ta,Ti,W,Zr)C high entropy ultra-high temperature ceramics were processed from commercial diboride and carbide powders with and without SiC additions. A 30-min hold at a maximum temperature of 1850 °C in spark plasma sintering resulted in a relative density of ∼95 %, which increased to ∼100 % with the addition of 7.5 wt.% SiC. The compositions did not reach chemical equilibrium under the given sintering conditions resulting in an inhomogeneous distribution of transition metals in both the boride and carbide phases. The addition of SiC improved densification by inhibiting grain growth, which reduced the grain size from 9.0 ± …

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