Devitrification Rates Of Fused Silica In The Presence Of Trace Impurities, 2016 University of Tennessee, Knoxville
Devitrification Rates Of Fused Silica In The Presence Of Trace Impurities, Nicholas Kivi, Adrian Moore, Kayla Dyar, Samuel Haaf
Chancellor’s Honors Program Projects
No abstract provided.
Magnetron Sputtering And Corrosion Of Ti-Al-C And Cr-Al-C Coatings For Zr-Alloy Nuclear Fuel Cladding, 2016 University of Tennessee - Knoxville
Magnetron Sputtering And Corrosion Of Ti-Al-C And Cr-Al-C Coatings For Zr-Alloy Nuclear Fuel Cladding, Devin Alan Roberts
The disaster at the Fukushima Daiichi Nuclear Power Plant in March 2011 bought renewed focus to the issue of corrosion in nuclear fuel cladding applications. This thesis reports on the background behind these issues, the investigation strategy, and the analysis of experiments focused on mitigating oxidation of Zr-alloy fuel cladding. This thesis seeks to develop magnetron sputtered Ti-Al-C and Cr-Al-C coatings for Zr-alloy substrates and characterize the as-deposited and corroded samples.
Ti-Al-C and Cr-Al-C coatings were deposited onto ZIRLO, Si, and Al2O3 [Aluminum Oxide] substrates under various sputtering conditions. A combinatorial sputtering method was employed to refine ...
Power Maximization For Pyroelectric, Piezoelectric, And Hybrid Energy Harvesting, 2016 Virginia Commonwealth University
Power Maximization For Pyroelectric, Piezoelectric, And Hybrid Energy Harvesting, Murtadha A. Shaheen
Theses and Dissertations
The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters.
A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance Cp and resistance Rp can be calculated at a frequency of 1 mHz to 1 Hz ...
New Nde Methods For Quality Assessment Of Advanced Ceramic Materials And Systems, 2016 Fraunhofer IKTS
New Nde Methods For Quality Assessment Of Advanced Ceramic Materials And Systems, Alexander Michaelis
Review of Progress in Quantitative Nondestructive Evaluation
Advanced ceramic materials offer enormous potential for innovations in the fields of efficient energy conversion and storage, propulsion systems, smart structures, sensor technology as well as environmental technology. The joint application of structural and functional ceramic technology allows for unique combination of electronic, ionic (electrochemical) and mechanical properties enabling the development of new, highly integrated systems in the above mentioned fields. However, due to the specific brittle failure mechanism of ceramic materials (Griffith behavior) the production of ceramic components requires new approaches for non destructive in-line testing. For this, we employ a broad variation of NDE methods such as x-ray ...
Texture Determination From Ultrasonic Wave Speeds For Hexagonal Close Pack And Cubic Materials, 2016 Imperial College London
Texture Determination From Ultrasonic Wave Speeds For Hexagonal Close Pack And Cubic Materials, Bo Lan, Michael J.S. Lowe, Fionn Dunne, P. E. Dunne
Review of Progress in Quantitative Nondestructive Evaluation
Crystallographic texture in polycrystalline hexagonal close pack (HCP) and cubic materials, often developed during thermomechanical deformations, has profound effects on properties at the macroscopic or component level. In this talk, a novel theoretical convolution model is presented, which couples the single crystal wave speed (the kernel function) with the polycrystal crystallographic orientation distribution function to give the resultant polycrystal wave speed function. Firstly developed on HCP  and then successfully extended to general anisotropic materials , the theoretical model expresses the three functions as harmonic expansions, thus enabling the calculation of any one of them when the other two are ...
A Novel Extrusion-Based Additive Manufacturing Process For Ceramic Parts, 2016 Missouri University of Science and Technology
A Novel Extrusion-Based Additive Manufacturing Process For Ceramic Parts, Amir Ghazanfari, Wenbin Li, Ming Leu, Gregory Hilmas
Faculty Publications, Mechanical Engineering
An extrusion-based additive manufacturing process, called the Ceramic On-Demand Extrusion (CODE) process, for producing three-dimensional ceramic components with near theoretical density is introduced in this paper. In this process, an aqueous paste of ceramic particles with a very low binder content (<1 vol%) is extruded through a moving nozzle at room temperature. After a layer is deposited, it is surrounded by oil (to a level just below the top surface of most recent layer) to preclude non-uniform evaporation from the sides. Infrared radiation is then used to partially, and uniformly, dry the just-deposited layer so that the yield stress of the paste increases and the part maintains its shape. The same procedure is repeated for every layer until part fabrication is completed. Several sample parts for various applications were produced using this process and their properties were obtained. The results indicate that the proposed method enables fabrication of large, dense ceramic parts with complex geometries.
Properties Of Partially Stabilized Zirconia Components Fabricated By The Ceramic On-Demand Extrusion Process, 2016 Missouri University of Science and Technology
Properties Of Partially Stabilized Zirconia Components Fabricated By The Ceramic On-Demand Extrusion Process, Wenbin Li, Amir Ghazanfari, Devin Mcmillen, Ming Leu, Gregory Hilmas, Jeremy Watts
Faculty Publications, Mechanical Engineering
The Ceramic On-Demand Extrusion (CODE) process is a novel additive manufacturing process for fabricating dense ceramic components from aqueous pastes of high solids loading. In this study, 3 mol% Y2O3 stabilized tetragonal zirconia polycrystal (3Y-TZP) parts were fabricated using the CODE process. The parts were then dried in a humidity controlled environmental chamber and sintered under atmospheric pressure. Mechanical properties of the sintered parts were examined using ASTM standard test techniques, including density, Young’s modulus, flexural strength, Weibull modulus, fracture toughness and Vickers hardness. The microstructure was analyzed, and grain size was measured using scanning electron microscopy. The results ...
Improving The Capacity, Durability And Stability Of Lithium-Ion Batteries By Interphase Engineering, 2016 University of Kentucky
Improving The Capacity, Durability And Stability Of Lithium-Ion Batteries By Interphase Engineering, Qinglin Zhang
Theses and Dissertations--Chemical and Materials Engineering
This dissertation is focus on the study of solid-electrolyte interphases (SEIs) on advanced lithium ion battery (LIB) anodes. The purposes of this dissertation are to a) develop a methodology to study the properties of SEIs; and b) provide guidelines for designing engineered SEIs. The general knowledge gained through this research will be beneficial for the entire battery research community.
Creep And Oxidation Of Hafnium Diboride-Based Ultra High Temperature Ceramics At 1500°C, 2015 Air Force Institute of Technology
Creep And Oxidation Of Hafnium Diboride-Based Ultra High Temperature Ceramics At 1500°C, Anthony J. Degregoria
Theses and Dissertations
Ultra high temperature ceramics (UHTCs) are leading candidates for aerospace structural applications in high temperature environments, including the leading edges of hypersonic aircraft and thermal protection systems for atmospheric re-entry vehicles. Before UHTCs can be used in such applications, their structural integrity and environmental durability must be assured, which requires a thorough understanding and characterization of their creep and oxidation behavior at relevant service temperatures.
Ion Irradiation-Induced Microstructural Change In Sic, 2015 University of Tennessee - Knoxville
Ion Irradiation-Induced Microstructural Change In Sic, Chien-Hung Chen
The high temperature radiation resistance of nuclear materials has become a key issue in developing future nuclear reactors. Because of its mechanical stability under high-energy neutron irradiation and high temperature, silicon carbide (SiC) has great potential as a structural material in advanced nuclear energy systems.
A newly developed nano-engineered (NE) 3C SiC with a nano-layered stacking fault (SFs) structure has been recently considered as a prospective choice due to enhanced point defect annihilation between layer-type structures, leading to outstanding radiation durability.
The objective of this project was to advance the understanding of gas bubble formation mechanisms under irradiation conditions in ...
Ion Irradiation Characterization Studies Of Max Phase Ceramics, 2015 University of Tennessee - Knoxville
Ion Irradiation Characterization Studies Of Max Phase Ceramics, Daniel William Clark
The family of layered carbides and nitrides known as MAX phase ceramics combine many attractive properties of both ceramics and metals due to their nanolaminate crystal structure and are promising potential candidates for application in future nuclear reactors. This thesis reports on the background, design, and analysis of an experiment focused on determining the effects of energetic heavy ion irradiations on polycrystalline samples of titanium silicon carbide 312, titanium aluminum carbide 312, and titanium aluminum carbide 211. The irradiation conditions consisted of ion doses between 10 and 30 displacements per atom at temperatures of 400 and 700 degrees Celsius, conditions ...
Cobalt Ferrite Nanoparticles Fabricated Via Co-Precipitation In Air: Overview Of Size Control And Magnetic Properties, 2015 Florida International University
Cobalt Ferrite Nanoparticles Fabricated Via Co-Precipitation In Air: Overview Of Size Control And Magnetic Properties, Dennis Toledo
FIU Electronic Theses and Dissertations
Cobalt Ferrite has important, size-dependent magnetic properties. Consequently, an overview of particle size is important. Co-precipitation in air was the fabrication method used because it is comparatively simple and safe. The effects of three different reaction times including 1, 2, 3 hour(s) on particle size were compared. Also, the effectiveness of three different capping agents (Oleic Acid, Polyvinylpyrollidone (PVP), and Trisodium Citrate) in reducing aggregation and correspondingly particle size were examined. Using Welch’s analysis of variance (ANOVA) and the relevant post hoc tests, there was no significant difference (p=0.05) between reaction times of 1 hour and ...
Influence Of The Counteranion On The Ability Of 1-Dodecyl-3-Methyltriazolium Ionic Liquids To Form Mesophases, 2015 Ruhr-Universitat Bochum
Influence Of The Counteranion On The Ability Of 1-Dodecyl-3-Methyltriazolium Ionic Liquids To Form Mesophases, Kathrin Stappert, Derya Unal, Eike T. Spielberg, Anja V. Mudring
Anja V. Mudring
The influence of the counteranion on the ability of the mesogenic cation 1-methyl-3-dodecyl-triazolium to form mesophases is explored. To that avail, salts of the cation with anions of different size, shape, and hydrogen bonding capability such as Cl–, Br–, I–, I3–, PF6–, and Tf2N– [bis(trifluorosulfonyl)amide] were synthesized and characterized. The crystal structures of the bromide, the iodide, and the triiodide reveal that the cations form bilayers with cations oriented in opposite directions featuring interdigitated alkyl tails. Within the layers, the cations are separated by anions. The rod-shaped triiodide anion forces the triazolium cation to align with it in ...
Grain Boundary Migration Of Nio-Mgo Alloys, 2015 Purdue University
Grain Boundary Migration Of Nio-Mgo Alloys, Xin Li Phuah, David Lowing, John Blendell
The Summer Undergraduate Research Fellowship (SURF) Symposium
Grain boundary engineering offers enhanced control of microstructure development during processing, leading to improved final material properties. However, using the effects of the interfacial energy anisotropy on grain boundary mobility to control microstructure development is not well understood. The NiO-MgO system is studied as it has complete solid solubility and a transition in the faceting behavior with composition due to changes in the interfacial energy anisotropy. NiO-MgO powders were produced through the amorphous citrate process and modifications to the process were made to reduce particle and agglomerate size. The powders were pressed and sintered in various conditions to produce fine ...
Development And Improvement Of Cerium Activated Gadolinium Gallium Aluminum Garnets Scintillators For Radiation Detectors By Codoping, 2015 University of Tennessee - Knoxville
Development And Improvement Of Cerium Activated Gadolinium Gallium Aluminum Garnets Scintillators For Radiation Detectors By Codoping, Fang Meng
Ce doped Gd3Ga3Al2O12 [gadolinium gallium aluminium oxides] is considered as a promising candidate for the next generation Positron Emission Tomography material due to its high light yield in theory. This dissertation is focused on studying the Gd3Ga3Al2O12:Ce crystals by codoping, aiming to improve the light yield and decay time experimentally and understand the underlying mechanism.
The work starts from prescreening appropriate codopants for Gd3Ga3Al2O12:Ce crystals. A cost-effective method is developed to predict the performance of the single crystals by characterizing the radioluminescence intensity and photoluminescence decay of the small polycrystalline pellets. This method is demonstrated by showing that ...
Ion Irradiation Induced Damage And Dynamic Recovery In Single Crystal Silicon Carbide And Strontium Titanate, 2015 University of Tennessee - Knoxville
Ion Irradiation Induced Damage And Dynamic Recovery In Single Crystal Silicon Carbide And Strontium Titanate, Haizhou Xue
The objective of this thesis work is to gain better understanding of ion-solid interaction in the energy regime where electronic and nuclear energy loss are comparable. Such responses of materials to ion irradiations are of fundamental importance for micro-electronics and nuclear applications. The ion irradiation induced modification for the crystal structure, the physical and chemical properties etc. may strongly affect the performance of functional materials that needs to be better understood.
Experimentally, ion irradiation induced damage accumulation and dynamic recovery in SiC [silicon carbide] and SrTiO3 [strontium titanate] were studied in this dissertation project. Five chapters are presented: Firstly ...
Crystal Growth And Physical Property Characterization Of Complex Perovskite Oxides, 2015 University of Tennessee - Knoxville
Crystal Growth And Physical Property Characterization Of Complex Perovskite Oxides, Ling Li
Bulk EuTiO3 [europium titanate], a quantum paraelectric antiferromagnet, is shown to exhibit multiferroic behavior in strained thin film form, which highlights the spin-phonon coupling in this system. We have investigated the structural, elastic, magnetic, thermal and transport properties of single crystals of EuTiO3 as well as doped system EuTi1-xBxO3 (B = Zr, Nb) [Zr and Nb doped europium titanate] utilizing various experimental techniques and theoretical calculations.
The cubic to tetragonal structural transition in pure EuTiO3 is characterized by a pronounced step-like softening of the elastic moduli near 288 K [kelvin], which resembles that ...
Disorder In Mg1-Xnixal2o4 Spinel And Its Impact On The Response To Swift Heavy Ion Irradiation, 2015 University of Tennessee - Knoxville
Disorder In Mg1-Xnixal2o4 Spinel And Its Impact On The Response To Swift Heavy Ion Irradiation, Brandon Alexander Perlov
Spinels, which are currently used in optical applications, have many proposed functions in the nuclear industry, such as a nuclear waste form due to its radiation resistance. Disordering plays a key role in the response of spinel to a wide range of irradiation conditions. The first part of this research project was on characterizing the type and degree of disorder that can be induced by chemical substitution in the magnesium nickel aluminate spinel solid solution series (Mg(1-x)Ni(x)Al2O4). Neutron total scattering has been used to characterize the structure at both the cation and anion sublattices. High-resolution pair ...
Computational And Experimental Studies Of Ca12al14o33, Mayenite, 2015 University of Tennessee - Knoxville
Computational And Experimental Studies Of Ca12al14o33, Mayenite, Elijah Duncan Barlow
In this study C₁₂Al₁₄O₃₃ [mayenite] is computationally modeled, synthesized, and compared to literature in order to build a knowledge base for the further study of this compound. It is hoped that this study of mayenite will lead to the development of a new transparent conductive oxide that uses earth abundant elements instead of rare earth elements. For this study polycrystalline mayenite was synthesized using traditional solid-state synthesis techniques, and growth of a single crystal was then attempted. The VASP software package was then used to simulate the compound, both physically and electronically. The results of the simulation were then compared ...
High Pressure Behavior Of Mullite-Type Oxides: Phase Transitions, Amorphization, Negative Linear Compressibility And Microstructural Implications, 2015 University of Nevada, Las Vegas
High Pressure Behavior Of Mullite-Type Oxides: Phase Transitions, Amorphization, Negative Linear Compressibility And Microstructural Implications, Patricia Kalita
UNLV Theses, Dissertations, Professional Papers, and Capstones
Even though mullite occurs rarely in nature, it is perhaps one of the most important phases in both traditional and advanced ceramics. Existing and emerging applications of mullite and mullite-type materials include: high-temperature composites, aerospace materials, ballistic shielding for military applications and even non-linear optical materials. There are many uncertainties regarding the basic physical properties of mullite-type materials, particularly in terms of their high-pressure structural stability and mechanical behavior that are important to address for emerging applications of mullites as engineering materials. This work is the first reported comprehensive investigation of the high –pressure structural behavior of several different mullites ...