Ceramic Materials Commons^™

Microstructural Evolution Of Zirconium Diboride Irradiated With 5–10 Mev Au Ions At Room Temperature And 570 °C, Narrie Loftus, José Olivares, Miguel Crespillo, Esther Enríquez Pérez, Jeremy Watts, Eric W. Bohannan, Gregory Hilmas, William Fahrenholtz, Joseph Graham

Materials Science and Engineering Faculty Research & Creative Works

Zirconium diboride was irradiated with 5 MeV Au^2 + , 7 MeV Au⁴⁺ and 10 MeV Au³⁺ ions at room temperature and 570 °C to doses from 1 to 8 displacements per atom (dpa). Grazing incidence X-ray diffraction (GIXRD) analysis revealed no secondary phase formation. Rietveld analysis of the GIXRD data indicated an accumulation of microstrain at low dpa and room temperature. Dislocations observed in transmission electron microscopy (TEM) cross-sections are likely the main contributor to the microstrain. High dpa and high-temperature samples exhibit lower lattice distortion than lower dpa samples, suggesting the presence of enhanced defect …

Thermally Stable Sic Particulate-Reinforced Sic Composites Up To 2000 ℃ Fabricated By Precursor Impregnation And Pyrolysis Method, Jian Gu, Vu Viet Hung, Lun Feng, William G. Fahrenholtz, Daejong Kim, Seyoung Kim, Sea Hoon Lee

Materials Science and Engineering Faculty Research & Creative Works

The thermo-mechanical properties of SiC particulate-reinforced SiC composites (SiC-PRCs), fabricated using precursor impregnation & pyrolysis (PIP) process, were analyzed up to 2000 ℃. The relative density of the SiC-PRCs after 4 PIP cycles was 88.6 %. The number of PIP cycles required decreased to nearly half compared with the conventional PIP method by using ultra-high concentration slurries up to 70 vol%. In addition, room-temperature bending strength (215 MPa) and Young's modulus (269 GPa) improved as the solid loading of the slurry increased. The bending strength increased to 232 MPa at 2000 ℃ in Ar. Despite the thermal deterioration of the …

A Software Package For Generating Robust And Accurate Potentials Using The Moment Tensor Potential Framework, Josiah Roberts, Biswas Rijal, Simon Divilov, Jon Paul Maria, William G. Fahrenholtz, Douglas E. Wolfe, Donald W. Brenner, Stefano Curtarolo, Eva Zurek

Materials Science and Engineering Faculty Research & Creative Works

We present the Plan for Robust and Accurate Potentials (PRAPs), a software package for training and using moment tensor potentials (MTPs) in concert with the Machine Learned Interatomic Potentials (MLIP) software package. PRAPs provides an automated workflow to train MTPs using active learning procedures, and a variety of utilities to ease and improve workflows when utilizing the MLIP software. PRAPs was originally developed in the context of crystal structure prediction, in which one calculates convex hulls and predicts low energy metastable and thermodynamically stable structures, but the potentials PRAPs develops are not limited to such applications. PRAPs produces two potentials, …

Superhard Refractory High-Entropy Diborides, M. D. Hossain, N. S. Mcilwaine, N. O. Marquez-Rios, A. C. Feltrin, V. Chawla, R. A. Mayanovic, W. G. Fahrenholtz, D. Penumadu, E. Zurek, D. W. Brenner, D. E. Wolfe, S. Divilov, H. Eckert, S. Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Using first-principles calculations and companion experimental validations, we demonstrate that the valence electron concentration (VEC) can be used to self-consistently parameterize the bonding characteristics of high-entropy diborides (HEBs) and in turn predict their mechanical properties. When VEC is 10.0 per formula unit (f.u.), HEBs enter the superhard category where Hv>40GPa because bonding states are optimally filled to resist shear deformation. Conversely, above or below a VEC of 10.0, the hardness decreases due to the filling of antibonding or the emptying of bonding states of the HEBs, respectively. This result is supported by analyses of the electronic structure, bonding, antibonding, …

Hardness Of (Hf,Ti,W,Zr)B2/(Hf,Ti,W,Zr)C-Based Ceramics With Varying Wb Content, Suzana Filipović, William G. Fahrenholtz, Gregory E. Hilmas, Nina Obradović, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Compositionally complex (Hf,Ti,Zr,W)B₂/(Hf,Ti,Zr,W)C-based ceramics were produced with different boride and carbide phase contents by varying the C/B₄C molar ratio used in boro/carbothermal reduction. A monoboride phase based on WB was detected in all compositions. As the C/B₄C ratio was varied, the WB content decreased from 23.7 vol% for a C/B₄C ratio of 6.0–15.3 vol% for a C/B₄C ratio of 10.3. Further increases in the C/B₄C ratio increased the WB content. The monoboride phase contained mainly W and Ti in a solid solution with the nominal composition of (W …

Integrated Computational And Experimental Investigation Of Groups V And Vi Metals In (M,Hf,Ti,Zr)B2-(M,Hf,Ti,Zr)C Ceramics, Ana C. Feltrin, Simon Divilov, Gregory E. Hilmas, Stefano Curtarolo, William G. Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Dual-phase compositionally complex ultra-high temperature ceramics were formulated by incorporating different Groups V and VI metals such as V, Nb, Ta, Cr, Mo, or W into a base composition containing the Group IV elements, Hf, Ti, and Zr. Metal distribution was predicted using first-principles-based thermodynamics simulations and compared with experimental results. Moreover, phase stability, microstructure, and mechanical properties were evaluated for all of the ceramics. Compositions containing Cr, V, Nb, or Ta formed dual-phase ceramics containing only one boride and one carbide phase, while compositions containing Mo or W developed an additional third phase. The experimental metal distribution trends generally …

Co-Calcination Of Limestone And Clay Enhances The Performance Of Limestone Calcined Clay Cement (Lc3), Oluwadamilare Charles Adesina, Sahil Surehali, Avinaya Tripathi, Kayla Lauren Lee, Bryan K. Aylas-Paredes, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Limestone-calcined clay cements (LC³) reduce the environmental impact of cement production and accelerate the industry transition toward carbon neutrality. While conventional LC³ with 50% clinker replacement (LC³-50) demonstrate long-term performance comparable to ordinary Portland cement (OPC) in concrete, early-age performance is generally compromised. This study explores for the first time, joint thermal treatment—that is, co-calcination—of limestone (LS) and bulk kaolinitic clay in mass ratios of 1:1 to 1:4 under a calcination regime specifically designed to ensure activation of the clay mineral. The co-calcination converts a small fraction of LS to metastable CaO, thus providing an …

Post-Calcium Treatment Evolution Of Alumina (Al2o3) Inclusions Morphology, Naziru I. Fuseini, Ronald J. O'Malley, Todd P. Sander, Jeffrey D. Smith, Haiming Wen, Laura N. Bartlett

Materials Science and Engineering Faculty Research & Creative Works

The post-calcium morphological evolution of Al₂O₃ inclusions formed under high-oxygen supersaturation (~1000 ppm) was investigated through time-resolved sampling and quenching of aluminum-killed, calcium-treated steel. SEM-EDS analysis revealed the formation of angular two-phase CaO·Al₂O₃–CaS inclusions within 1 minute, gradually transforming into spherical liquid 12CaO·7Al₂O₃ and CaO·Al₂O₃ with a thin CaS layer around it. The 3D morphology of the CaS phase of the complex CaO·Al₂O₃–CaS inclusions observed at 1 minute appeared as a cone-cap attached to the partially modified CaO·Al₂O₃. This …

Thermodynamic Analysis Of Metal Segregation In Two Metal Boride-Carbide Ceramics Containing V With Cr, Hf, Ti, Or Zr, Ana C. Feltrin, Simon Divilov, Gregory E. Hilmas, Stefano Curtarolo, William G. Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Dual-phase carbide-boride ceramics in different vanadium-Me (Me = Cr, Hf, Ti, and Zr) binary systems were synthesized by boro/carbothermal reduction under stoichiometric and carbon-deficient conditions and densified by spark plasma sintering. Thermodynamic analysis was used to evaluate the influence of composition on the phase stability and metal segregation between phases, along with the resulting effects on microstructure and hardness. Pairing vanadium with Group IV elements (Hf, Ti, and Zr) consistently formed one boride and one carbide phase, while the Cr-V system formed a monoboride phase and a carbon-deficient carbide. Metal segregation trends depended on composition. Vanadium preferentially segregated to the …

Zirconium And Hafnium Interdiffusion Study In Zrb2–Hfb2 System, Yue Zhou, Ana C. Feltrin, William G. Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Interdiffusion of Zr and Hf in the diboride system was investigated. High-purity zirconium diboride (ZrB₂) and hafnium diboride (HfB₂) were prepared by a combination of boro-/carbothermal reduction synthesis and densification by spark plasma sintering. The bulk ceramics had relative densities of 99.3% for ZrB₂ and 99.7% for HfB₂, and both ceramics were phase-pure by x-ray diffraction analysis. Diffusion couples of ZrB₂ and HfB₂ were annealed at temperatures ranging from 2000°C to 2200°C for times from 4 to 12 h. Zr and Hf elemental concentration profiles were measured using energy dispersive spectroscopy …

Fly Ash Proppant Developed For Hydraulic Fracturing, Raz Rzgar Haydar

Theses and Dissertations

Proppants are critical components in hydraulic fracturing, used to maintain fracture conductivity and enhance reservoir stimulation. In high-pressure and harsh reservoir environments, the use of high-strength proppants is essential to ensure well performance. Conventional proppants, being sand, ceramic, and sintered bauxite can be expensive, and their use often requires costly fracture fluids. This study investigates the possibility of utalizing fly ash geopolymers as a sustainable alternative that is also cost-effective for proppants manufacturing. Fly ash, a by-product from the combustion of coal and other materials, was explored as a base material for proppants, utilizing an alkaline solution as an activator …

Raw Data For The Manuscript "Silicon-Stabilized Three-Dimensional Covalent Networks In High Entropy Diborides", Michael Yeung, Reza Mohammadi

Chemistry Department Faculty Scholarship

Abstract for data:

Raw data for the journal publication, Silicon-stabilized three-dimensional covalent networks in high entropy diborides. ReadMe file provided.

Abstract for Journal publication: 

High entropy ceramics offer a pathway to stabilize unconventional chemistries beyond traditional alloying rules. We report the incorporation of silicon into an AlB₂-type high entropy diboride, Cr_0.2Nb_0.2Si_0.2Ta_0.2Ti_0.2B₂, despite silicon violating classical Hume-Rothery rules for alloying. Arc melting produced a phase-pure, chemically homogeneous structure, as confirmed by powder X-ray diffraction (pXRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDS). Silicon occupies …

Specialty Glass Fibers For Optical Applications, Theodore Carver Lewis

Masters Theses

"Fibers were draw from melts of a commercial Na-aluminosilicate for ion-exchange treatments. A process was developed to draw 100-meters of fiber with a diameter of 100±10m. The fibers were sectioned for ion exchange treatments. SEM analysis showed an ion penetration depth of 45um after 4 hours of ion exchange in a 400°C KNO3 salt bath. The pristine and ion-exchanged fibers were characterized by a two-point bend test in room temperature air with controlled relative humidity (RH) and faceplate velocities between 100 and 4000 μm/s to characterize fatigue effects. Pristine fibers tested in air (40% RH) at 4000 μm/s had failure …

Strontium Titanate For Capacitor And Energy Storage Applications At Cryogenic Temperatures, Hung Trinh

Doctoral Dissertations

This study investigates the dielectric properties of single crystal and ceramic strontium titanate (SrTiO₃) for cryogenic capacitor applications from room temperature to 4 K. Permittivity (k) and loss tangent are dependent on temperature, frequency, mechanical stress, and applied DC electric field. Accordingly, the dielectric constant and loss tangent were measured at various frequencies and DC bias levels. Loss tangent data are also presented as equivalent series resistance (ESR). For single crystal SrTiO₃, an impurity level of ≈500 ppm barium resulted in an increase of the maximum permittivity to approximately 50,000 at 6 K. This relatively high …

Zirconium Carbide Based Materials For Extreme Aerospace Environments, Nathaniel Hyman Blatt

Doctoral Dissertations

This research focuses on the processing and properties of zirconium carbide-based materials to promote their use in extreme environment aerospace applications, including nuclear thermal propulsion and hyper sonics. Several carbide systems including ZrC, ZrC-Mo cermets, (Zr, Nb)C, and a high entropy carbide were developed. The ZrC-Mo cermet was studied extensively to understand the effect of starting carbide grain size on the final microstructure, composition, elastic moduli, hardness, fracture toughness, room and elevated temperature flexural strength, thermal diffusivity, electrical resistivity, thermal expansion coefficient, and thermal conductivity. It was shown that heat transport in the cermets was dominated by the ZrC phase …

Mitigating Hysteresis In Metal-Coated Fibers Via Optimized Thermal Treatment For Advanced Distributed High-Temperature Sensing Applications, Koustav Dey, Rony Kumer Saha, Bohong Zhang, S. Narasimman, Farhan Mumtaz, Jeffrey D. Smith, Rex E. Gerald, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Metal-coated optical fibers are widely employed in sensing applications owing to their superior mechanical strength and corrosion resistance. However, their calibration at elevated temperatures is hindered by hysteresis, manifested as discrepancies between heating and cooling cycles, primarily caused by residual strain from mismatched thermal expansion coefficients (TECs) between the metal coating and silica cladding. This research introduces an optimal heat treatment procedure aimed at minimizing the impact of the mismatch in TECs between the cladding and the coating materials that causes the residual strain in gold (Au) and copper (Cu) coated fibers for achieving reliable distributed high temperature sensing up …

Waveguide-Assisted Single-Mode Fiber Bragg Gratings In A Highly Multimode Coreless Fiber Via Femtosecond Laser Inscription For Extreme Temperature Quasi-Distributed Thermal Sensing, Farhan Mumtaz, Koustav Dey, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research reports a potential quasi-distributed thermal mapping optical sensing system for extreme temperatures, leveraging femtosecond (fs) laser inscribed single-mode fiber Bragg gratings (FBGs) and a waveguide within coreless, highly multimode optical fiber, resulting in a single-mode structure. Unlike doped single-mode fibers, coreless fibers composed of silica rods prevent issues associated with dopant migration and ensure data accuracy. The strategic placement of point-by-point FBGs in a cascaded formation on the fs-laser inscribed waveguide facilitates localized multipoint sensing. The long-term stability of the proposed waveguide-assisted FBG system was assessed over 24 hours at elevated temperatures (1000°C), showing no hysteresis during heating …

Bridging Physics-Based Modeling And Machine Learning To Predict Material Behavior: Applications In Fatigue Crack Growth And Dielectric Property Characterization, Ansan Pokharel

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation integrates physics-based modeling with machine learning (ML) to predict how materials behave under complex thermal and mechanical conditions. A key innovation of this work is the use of finite element analysis (FEA) to supplement experimental data. This approach creates more diverse and representative synthetic datasets, helping to reduce the limitations and biases that arise when training ML models solely on experimental measurements. The research focuses on two applications: improving the prediction of fatigue properties in superalloys and estimating temperature-dependent, high-frequency dielectric properties relevant to microwave-based chemical processing.

In the first study, low-cycle fatigue experiments were performed on the …

A Study In The Advanced Manufacturing Of Full Solids Oxide Fuel Cells (Sofcs) Via Aerosol Deposition (Ad) Methods With Macro- And Microstructural Defect Characterization, Davis A. Warmuth

Graduate Theses, Dissertations, and Problem Reports (ETD)

The goal of this work is to 3D print a full SOFC layer-by-layer using aerosol deposition (AD) at a resolution of 5 μm. To achieve this goal, several studies were undertaken to develop and optimize an AD system to use ceramic inks. A 130 kHz AD system was developed with 4 material pumps to allow for depositions of individual compositions of the in-situ mixture of multiple solutions to allow for the fabrication of functional gradients in three dimensions. This system was then programmed to deposit air electrode layers containing different material ratios and porous microstructures, comparing their electrochemical performance to …

General Approach To Determining The Embodied Energy Of Refractory Products, Jacob A. Kerr

Masters Theses

"Refractories are an important group of engineered materials that are critical for sustaining life in the modern age. These products are key components in many industrial processes, such as the production of steel, cement, glass, aluminum, copper, lead, and many others. It is estimated that 50 million tons of refractory products are produced and used around the world every year. Of this, an estimated 28 million tons of spent refractory is generated after use, much of which ends up in landfills all over the globe. By utilizing embodied energy methodologies, a complete sum of energy inputs can be mapped throughout …