Ceramic Materials Commons^™

Engineering Ceramic Ductility Into Aluminum Oxide, Krish Bhuva

Holster Scholar Projects

This project explores the enhancement of ductility in Aluminum Oxide (Al₂O₃) ceramics through microstructural engineering. The goal is to combine the hardness and stability of Al₂O₃ with enhanced ductility for diverse industrial applications. Inspired by the naturally occurring Itacolumite rock, known for its complex microstructure, this research aims to replicate similar microstructural features in engineering ceramics. By doping Al₂O₃ with Titanium Dioxide (TiO₂), Boron Nitride (BN), and a pore former, while employing innovative sintering techniques, we hypothesize that these modifications will lead to a measurable increase in ductility. Despite early challenges in achieving homogeneity in sintering, promising results were observed …

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 …

Kinetic Modeling Of Dust Grain Dynamics In Electrostatic Sieving, Aaron Berkhoff, Easton Ingram, Fateme Rezaei, Jeffrey Smith, David Bayless, William Schonberg, Daoru Han

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new kinetic particle modeling framework was developed to investigate electrostatic transport of lunar regolith dust particles with applications to the concept of electrostatic sieving. the new approach is based on kinetic particle dynamics and includes major modules of sampling the particle size distribution, solving electric fields, and tracking motion of charged dust grains. a case study for a concept of electrostatic sieving was chosen to validate the new model. the simulation achieved similar performance of particle size classification as reported in the literature. the new model is computationally efficient (takes a few minutes on a PC-type laptop computer) so …

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 …

Degradation Study Of Single Crystal Barium Titanate Capacitors Under Harsh Environment, Menglin Wang

Electrical Engineering Theses and Dissertations

Capacitors are critical for voltage source converter functionality. DC-link capacitors are known to have reliability issues. Resistance degradation at high temperatures is one of the primary failure modes in capacitors. The overall goal of this program is to improve the understanding of high voltage breakdown and resistance degradation in high dielectric constant inorganic ceramic capacitors, using single crystal BaTiO₃ as a model system to understand the impact and control of oxygen vacancy migration to maximize the long-term reliability of high voltage inorganic multi-layer ceramic capacitors, which allows higher frequency operation, reducing the size and cost of passive components in …

Engineering The Properties Of Magnesium Aluminate Spinel Through Solid State Solutions, Robin Conner

All Theses

Magnesium aluminate spinel solid state solutions were prepared via the coprecipitation method and calcined in air at 900 °C for 2 h. The manipulation of magnesium aluminate spinel’s microstructure through the formation of solid state solutions with zinc and gadolinium substituting for magnesium was investigated. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) confirmed the formation of a single cubic crystalline phase. The luminescence properties were investigated by radioluminescence (RL) under X-ray excitation and thermoluminescence (TL) measurements. In the case of zinc, all concentrations of the solid state solutions showed similar luminescence with bands at …

Secondary Electron Yield Of Metals, Alloys, And Metal Oxides From First Principles Based Monte Carlo Simulations, Raul E. Gutierrez

Electrical and Computer Engineering ETDs

Density Functional Theory (DFT) based Monte Carlo (MC) simulations of the Sec-
ondary Electron Yield (SEY) of metals, alloys, and metal oxides are performed to
find material properties that could help reduce or influence the multipactor effect.
In order to accurately model the SEY of materials, knowledge of the frequency- and
momentum-dependent Energy Loss Function (qDepELF) is required. The qDepELF
is difficult to determine from experiment; however, it can be calculated from first
principles. The DFT-MC approach for simulating the secondary electron genera-
tion, propagation, and emission processes is described herein. Material properties,
which are calculated using DFT and used …

Tension–Compression Fatigue Of A Hybrid Polymer-Matrix/Ceramic-Matrix Composite At Elevated Temperature, Marina B. Ruggles-Wrenn, Joshua Schmidt

Faculty Publications

Fully reversed tension–compression fatigue of a hybrid material comprising polymer matrix composite (PMC) co-cured with a ceramic matrix composite (CMC) was investigated. The PMC portion had a polyimide matrix reinforced with 15 plies of carbon fibers woven in an eight-harness satin weave (8HSW). The CMC portion had three plies of a quartz-fiber 8HSW fabric in a zirconia-based ceramic matrix. The hybrid PMC/CMC was developed for use in aerospace thermal protection systems (TPS). Hence, the experimental setup aimed to simulate the TPS service environment—the CMC side was kept at 329 °C, whereas the PMC side was open to laboratory air. Compression …

Pulsing-Induced Healing Of A Surface Crack Of A Nickel-Based Alloy, Liwei Wang, Mingming Quan, Zhen Tan, Ming Liu, Dianlong Wang, Xiao Yang, Ying Liu, Yaning Mao, Zhimin Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

In this work, we demonstrate the feasibility of applying electric pulses to heal surface cracks on nickel-based alloy GH4169 under compressive load. There exists an incubation time for the onset of the healing of a crack, which is associated with local temperature at the crack tip. The crack size decreases with increasing the pulsing time at a constant healing rate prior to complete healing of the crack. Increasing compressive load accelerates the healing process. The electric pulsing leads to the formation of an influential zone surrounding the crack with the finest grain sizes in the healed crack and the coarsest …

Waste Illuminates Worlds: Printed Modular Lamp Design Based On Brick And Clay Tile, Yechen Zhu

Masters Theses

The building industry in the New England area is often in a state of entropy, with abandoned brick buildings contributing to urban decay. The recycling rate of brick and clay tile wastes generated by construction and demolition is only 12.2%, meaning the majority is sent to landfills. The expansion of landfills can lead to significant environmental and community challenges, including increased traffic from waste transport, habitat destruction, ecosystem degradation, and contributions to climate change. Specifically, the Bethlehem landfill in New Hampshire, which is planned to undergo a 5.71-acre lateral expansion through 2026, has already encountered issues such as leachate spills …

Non-Linear Modeling Of Hysteresis In Piezoelectric Actuated Cantilever Beam Using The Bouc-Wen Model, Andrew Donald Maas

Master's Theses

Piezoelectric actuators frequently exhibit a time-dependent behavioral phenomenon known as hysteresis, resulting in a lag in the deformation of the actuator compared to linear models. The presence of hysteresis complicates control systems involving piezoelectric actuators. However, traditional modeling methods for piezoelectric actuated smart structures often treat the piezoelectric patches as linear actuators without considering hysteresis, leading to suboptimal controller performance.

This thesis aims to establish a comprehensive model by integrating the Euler-Bernoulli beam bending model with the hysteresis dynamics induced by two opposing piezoelectric patches attached to a beam. A model expansion method is employed to transform the partial differential …

Interaction Of Particles With Plasma And Shock Produced By Pulsed Spark Discharge, Shomik Mukhopadhyay

Dissertations

Interactions of powders with high-temperature plasma and shockwaves occur in diverse scenarios, such as nuclear blasts, accidental industrial dust explosions, solid propellant combustion in explosive charges and when removing contaminants from surfaces. Electrostatic Discharge (ESD), known for generating shock and plasma, is a promising lab-scale technique for simulating these interactions. Studies with ESD involved placing powders near a spark-producing gap between electrodes and observing mechanical and chemical processes like particle motion and ignition. A limited range of spark conditions and material properties have been tested, which facilitated the development and validation of preliminary computational models describing this system. Significant gaps …

Characterization Of Platinum On Carbon Nanoparticles Selectively Coated With Titanium Nitride (Tin), Matthew Maramo

Honors Scholar Theses

Proton exchange membrane fuel cells are a promising low-carbon technology that still face problems including low durability during their normal operation cycles. At the cathode, the carbon supports of the catalysts may corrode. Atomic layer deposition of titanium nitride is performed on prepared catalyst layer samples. The purpose of the deposition is to create a thin film over the carbon supports to reduce carbon support corrosion and improve the lifespan of the fuel cell. Sheet resistances and contact angles are measured for the samples before and after the deposition, although some samples did not receive the deposition and post-deposition characterization …

Thermal Conductivity Of Thin Porous Ceramic Coatings: An Analytical And Experimental Study, Lei Zhao

Theses and Dissertations

An analytical model of the thermal conductivity of the porous yttrium-stabilized zirconia (YSZ) layer used in the thermal barrier coatings (TBCs) is presented. Such high-temperature resistant coatings are essential to protect the metallic components of gas turbine engines. The model calculates the conductivity based on the coating's porosity, pore size distribution, and pore morphology, including the individual pore cross-section area, aspect ratio, and orientation, which are extracted from the scanning electron microscopy images. The model was verified through comparisons with numerical simulation results from a multiphysics software tool. A laser temperature gradient test was performed to validate the analytical model …

Smart Manufacturing Of Cement: From Lab-Scale Simulation And Testing To Industry-Scale Deployment., Juan David Tabares Tamayo

Electronic Theses and Dissertations

Cement kilns are controlled by experienced process operators who follow experience-based industry guidelines using data collected and fundamental knowledge. The manufacturing process, which is equipped with sensors and equipment, transfers data/information to the operators to aid standardized decision-making operations. In contrast, companies have used such data to develop and implement digital solutions for predictive control systems; in effect, FLSmidth and Rockwell Automation. However, despite the availability of automated control systems and investigation in automation for process monitoring and optimization, opportunities to radically optimize cement manufacturing are still abundant and in need of implementation. Therefore, this research developed simulation models and …

Layered Structure Protonic Ceramic Conductors Of The Form Ba5in2+Xal2zr1-Xo13-Δ, Nathan Cretegny

All Theses

In this work, the hexagonal perovskite of targeted composition Ba₅In_2+xAl₂Zr_1-xO₁₃ (x=0, 0.1, 0.2) was synthesized via a solid-state synthesis route to study the impact of oxygen vacancy concentration in layered hexagonal perovskites. Precursor oxides were mixed in stoichiometric proportions, calcined between 800-1200℃ and sintered at 1475℃. The sintered pellets were crushed into fine powders to investigate the chemistry and structure through X-ray diffraction, neutron diffraction, inductively coupled plasma mass spectrometry, and nuclear magnetic resonance. Dense pellets were used to study conductivity properties using electrochemical impedance spectroscopy.

The synthesis approach produced 100% …

Machine Learning Assisted Discovery Of High-Performance Perovskites For Hydrogen Production, Ximei Zhai

All Dissertations

Hydrogen has significantly contributed to the global energy transition as a clean energy carrier. However, traditional hydrogen production involves energy-intensive processes with heavy carbon emissions. High-temperature water splitting to generate hydrogen has become a promising route for clean hydrogen production. Directly utilizing concentrated solar heat to perform solar thermochemical hydrogen (STCH) production is considered one of the most eco-friendly hydrogen production options. At the same time, high-temperature electrolysis in protonic ceramic electrolysis cells (PCECs) can efficiently utilize intermittent and cost-effective renewable electricity to produce hydrogen. Perovskite oxides with good redox capability and tolerance for oxygen deficiency are considered the most …

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 …

Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul

Makara Journal of Science

Ancient potteries offer valuable information regarding technological advancements, life dynamics, cultural diversity, and trade routes in the past. Earthenware, stoneware, and porcelain from Southeast Asia have been characterized using several analytical techniques, as reviewed in this article. Fluorescent and diffracted X-rays give rise to elemental and phase compositions, respectively. Examination of molecular bonds requires vibrational spectroscopy, which is useful for the identification of organic materials in ancient potteries. With the advent of portable X-ray fluorescence and Raman spectrometry, on-site analysis of archeological ceramics is now possible. For in-depth analysis, synchrotron light sources can provide new insights into artifacts through X-ray …

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 …

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.

Influence Of Environmental Barrier Coatings On The Overall Effectiveness Of A Film Cooled Ceramic Matrix Composite Plate, Shane P. Lindsay

Theses and Dissertations

Silicon carbide ceramic matrix composites, a promising new potential upgrade over the conventional metals currently used for jet engine turbine blades, have a propensity to oxidize in a combustion environment. Engine manufacturers often apply environmental barrier coatings to prevent the composites from oxidizing. What is unclear, however, is how environmental barrier coatings effect underlying composite temperatures. This research examined the coatings’ effects by first characterizing the influence of environmental barrier coatings on the underlying temperature of a protected ceramic, then evaluating the significance of lateral conduction for cooling a coated ceramic, and finally comparing cooling results for coated and uncoated …

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 …

Degradation Of The Mechanical Properties And Hydrogen Generation In Cement Under Gamma Irradiation Assessed By Atomistic Simulation, Omar Al Najjar

Theses and Dissertations

Although understanding the effect of the gamma-ray on cement-based materials is essential for many applications, such as the concrete contaminate of nuclear reactors or the storage of radioactive waste in cement-based waste forms, such understanding is still not fully developed. The importance of having such an understanding is becoming of utmost importance, especially with calls to extend the lifetime of nuclear power plants, and also due to some recent incidents of failures of the concrete structure in the nuclear fields. In this work, the details of preparing three molecular models as a representative structure of the main binding phase of …

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 …

Processing & Properties Of Zirconium Carbide Manufactured By Ceramic On-Demand Extrusion, Clare Sabata

Masters Theses

"This research focuses on the development of a zirconium carbide (ZrC) paste for use in material extrusion direct ink write additive manufacturing (AM) followed by the pressure less densification of ZrC and the mechanical and thermal characterization of the resulting ceramics. A highly loaded, aqueous paste was developed using commercial ZrC powder ball milled to ~1 μm. Optimal dispersant, binder, and solids loading were found by rheological characterization. The paste composition consisted of 46-47 vol% ZrC, 43.5 vol% distilled water, 8.1 vol% dispersant, and 1.6 vol% binder. A yield stress of ~8 Pa allowed for shape retention upon removal of …

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 …

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 …

Phenolic Polymer Infiltration And Pyrolysis Process For Additively Manufactured Carbon/Peek Composites To Produce Carbon–Carbon Composites, S. Weiler, H. A. Haffner, K. Chandrashekhara, J. Watts, G. E. Hilmas, J. Bayldon, L. M. Rueschhoff

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Carbon–carbon composites are carbon fibers reinforced with carbon matrix and are classified as advanced materials well suited for high-temperature structural applications. Carbon–carbon composites are characterized by maintaining excellent mechanical properties and structural stability at high temperatures and have been used in aerospace application as nozzles, heatshields, and leading edge. However, conventional methods to manufacture carbon–carbon composites are costly and time-consuming. the aim of this work is to develop a method for creating additively manufactured (AM) carbon–carbon composites using a high-pressure re-infiltration process. in doing so, less infiltration cycles are required compared to a low-pressure re-infiltration, reducing the total manufacture time. …

Electrostatic Sorting Of Lunar Regolith Simulants For Sustainable Resource Utilization: Modeling And Characterization Of Particle Size Distribution, Abdullah Al Moinee, Peter Bachle, Kyle Newport, William Schonberg, David Bayless, Jeffrey Smith, Daoru Han, Fateme Rezaei

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In pursuit of sustainable resource utilization on the Moon, this paper delves into modeling and characterization of particle size distribution (PSD) of lunar regolith simulants in an electrostatic system. A prototype electrostatic sieve was built and tested with four sample simulants mirroring properties of lunar mare and highland regolith. An alternating four-phase (90 degrees, 180 degrees, 270 degrees, 360 degrees) traveling square-wave was utilized for particle-directed transport to model the diverse trajectories of the particles. Numerically, we scrutinized how the distribution functions of the particles are manifested as the electrostatic field propagates, with a focus on three distinct particle ranges …