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Articles 271 - 300 of 1335

Full-Text Articles in Materials Science and Engineering

A Kinetic Evaluation For Phenothiazine Base Copolymers, Fatih Dogan Jan 2021

A Kinetic Evaluation For Phenothiazine Base Copolymers, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

In here, the non-isothermal decomposition kinetics of co-polymers-based phenothiazine was present-ed. For this, firstly, 3, 7-di-2-thienyl-10H-phenothiazine (TF) was prepared via an optimized Suzu-ki–Miyaura cross-coupling reaction. After monomer (TF) characterization, the copolymerization re-actions with EDOT and thiophene were performed by the electrochemical technique. The molecular masses of the co-polymers were found by gel permeation chromatography (GPC) analysis. Thermal characterizations of the resulting polymers were conducted by thermogravimetric analyses. The thermal decomposition kinetics of the resulting polymers was also performed. For this, the kinetic methods (Tang, FWO, KAS, Kissinger, and Friedman) based on the multiple heating rates were used. Several kinetic parameters …

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Degradation Issues And Stabilization Strategies Of Protonic Ceramic Electrolysis Cells For Steam Electrolysis, Hanrui Su, Yun Hang Hu Jan 2021

Degradation Issues And Stabilization Strategies Of Protonic Ceramic Electrolysis Cells For Steam Electrolysis, Hanrui Su, Yun Hang Hu

Michigan Tech Publications, Part 1

Protonic ceramic electrolysis cells (PCECs) are attractive electrochemical devices for converting electrical energy to chemicals due to their high conversion efficiency, favorable thermodynamics, fast kinetics, and inexpensive materials. Compared with conventional oxygen ion-conducting solid oxide electrolysis cells, PCECs operate at a lower operating temperature and a favorable operation mode, thus expecting high durability. However, the degradation of PCECs is still significant, hampering their development. In this review, the typical degradations of PCECs are summarized, with emphasis on the chemical stability of the electrolytes and the air electrode materials. Moreover, the degradation mechanism and influencing factors are assessed deeply. Finally, the …

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Metal Supported Solid Oxide Fuel Cell Using Proton Conducting Electrolyte For Direct Ammonia Utilization, Edwin Vega Hiraldo Jan 2021

Metal Supported Solid Oxide Fuel Cell Using Proton Conducting Electrolyte For Direct Ammonia Utilization, Edwin Vega Hiraldo

Graduate Theses, Dissertations, and Problem Reports (ETD)

Transportation represents about 27% of global warming greenhouse gas emissions nowadays. To reduce these emissions, fuel cell electric vehicles have been poised to be a new trend to provide zero-emission transportation. Among them, solid oxide fuel cells (SOFCs) offer efficient, clean energy, especially when powered by carbon-free fuel, such as ammonia. To enable onboard ammonia-fed SOFCs, a metal-supported, proton-conducting SOFC is investigated in this study. The metal support would provide physical robustness for thermal shock during vehicles’ quick start-up and shutdown, reduce internal temperature gradients due to the greater thermal conductivity of the metal, and enable conventional metal joining for …

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Reclamation Of Fused Silica From Investment Shells Used For Casting Steel, Samuel L. Holt Jan 2021

Reclamation Of Fused Silica From Investment Shells Used For Casting Steel, Samuel L. Holt

College of Graduate Studies: Theses & Dissertations

Fused silica is widely used for investment casting shell molds. Fused silica shells are discarded after being used for casting one time. This is due to the transformation of fused silica to beta cristobalite above 1652℉ (900℃). To reduce cost and waste of investment casting foundries, this study is exploring a method to inhibit transformation of fused silica and reclaim it from high temperature investment casting shells. This research has employed firing to minimalize fused silica transformation to cristobalite. The phase transformation is minimalized due to sintering and coarsening of the particles during firing. Coarsening reduces surface area to volume …

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Improving Performance And Durability Of Intermediate Temperature Proton‐Conducting Solid Oxide Electrolysis Cells Via Materials Design And Catalyst Surface Engineering, Hanchen Tian Jan 2021

Improving Performance And Durability Of Intermediate Temperature Proton‐Conducting Solid Oxide Electrolysis Cells Via Materials Design And Catalyst Surface Engineering, Hanchen Tian

Graduate Theses, Dissertations, and Problem Reports (ETD)

Solid oxide steam electrolysis cell, a promising electrical-chemical conversion device for the next generation efficient hydrogen production and energy storage, has been actively studied because of their high energy conversion efficiencies and prospective applications as electrochemical reactors. After decades of research on protonic ceramic materials, remarkable advances have been made in the protonic ceramic electrochemical cells (PCECs) air electrode and electrolyte. However, the existing air electrodes are far from satisfying the requirements of practical applications, a series of issues, including the lack of active and durable electrodes, greatly limit the commercialization. To date, the systematic development of triple conducting catalysts …

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Increasing The Seebeck Coefficient Of Thermoelectric Calcium Cobaltite Ceramics Through Incorporation Of Rare-Earth Elements, Andre Fabian Fernandes Jan 2021

Increasing The Seebeck Coefficient Of Thermoelectric Calcium Cobaltite Ceramics Through Incorporation Of Rare-Earth Elements, Andre Fabian Fernandes

Graduate Theses, Dissertations, and Problem Reports (ETD)

The demand for alternative sources of energy continues to grow, so it is essential to look for alternatives that are environmentally sustainable to minimize the environmental impact of energy generation. Projections suggest that renewables have the potential to make up over fifty percent of power generation by 2035. Studies have shown that in 2020 more than 62% of the energy produced in the US was lost, with most of this energy being in the form of waste heat. Waste heat can be utilized to improve the efficiency of power production or even power other devices. This waste heat can be …

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Contributions To The Performance Of Thin Film Capacitors For High Reliability Applications, Daniel Krueger Jan 2021

Contributions To The Performance Of Thin Film Capacitors For High Reliability Applications, Daniel Krueger

Doctoral Dissertations

"Capacitors are critical devices in microelectronic assemblies that must be incorporated into electronic systems through a variety of ways such as integrated or discrete devices. This work has developed new thin film capacitors deposited directly onto multichip module or printed circuit board surfaces to benefit from closer integration that enhances system performance for use in high reliability applications. The capacitors serve as filters or provide tuning and energy storage functions. Unexpected performance was observed during development that included low adhesion of the films to the substrates, higher effective dielectric constants than reported in literature, and low yields. Three publications resulted …

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Thermal And Mechanical Properties Of Novel Carbide Materials, Evan Charles Schwind Jan 2021

Thermal And Mechanical Properties Of Novel Carbide Materials, Evan Charles Schwind

Doctoral Dissertations

"This research focuses on studying the thermal and mechanical properties of novel carbide materials at room and elevated temperatures. The novel carbide materials investigated include zeta phase tantalum carbide (ζ-Ta4C3-x) and a high entropy (Ta,Hf,Nb,Zr)C carbide. The electrical resistivity and thermal conductivity of zeta phase tantalum carbide (~96 wt.%) were measured as 160 ± 4.2 μΩ-cm and 9.6 W/m•K. These are higher and lower (respectively) than for cubic tantalum carbide, most likely due to planes of carbon vacancies present in the ζ-Ta4C3-x crystal structure. The thermal conductivity of (Ta,Hf,Nb,Zr)C was lower than any …

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Effect Of Applied Pressure During Sintering On The Densification And Mechanical Properties Of Sicf/Sic Composites Prepared By Electrophoretic Infiltration, Alfian Noviyanto Dec 2020

Effect Of Applied Pressure During Sintering On The Densification And Mechanical Properties Of Sicf/Sic Composites Prepared By Electrophoretic Infiltration, Alfian Noviyanto

Makara Journal of Science

SiC-fiber-reinforced SiC matrix ceramic (SiCf/SiC) composites were successfully fabricated by electrophoretic infiltration and sintering at various applied pressures. The effect of applied pressure (i.e., 5, 10, and 20 MPa) was thoroughly examined, and applied pressure appears to influence the densification and mechanical properties of SiCf/SiC composites. The densities of SiCf/SiC composites prepared at applied pressure of 5, 10, and 20 MPa were 2.99, 3.10, and 3.16 g/cm3, respectively. All samples showed dense microstructures in their matrix areas; however, many closed pores were found with increasing pressure. Pressure induced densification in the fiber …

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Numerical Evaluation Of Effective Thermal Response Of Heterogeneous Materials, Kevin W. Irick Dec 2020

Numerical Evaluation Of Effective Thermal Response Of Heterogeneous Materials, Kevin W. Irick

Mechanical Engineering ETDs

Heterogeneity in materials leads to increased complication of physics, at the level or scale where heterogeneity exists, making analysis and material behavior predictions more difficult. As a result of the intricate descriptions or understanding of the physics required to determine the behavior of a heterogenous material or system, practitioners frequently prefer the use of effective properties or responses. This body of work is dedicated to performing computational analyses on the thermal behavior of heterogeneous materials and evaluating the corresponding analyses using formal verification approaches. Custom finite element method code was used for solving the heat equation in a variety of …

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Manipulating Air-Gap Electrospinning To Create Aligned Polymer Nanofiber-Wrapped Glass Microfibers For Cortical Bone Tissue Engineering, Houston R. Linder, Austin A. Glass, Delbert E. Day, Scott A. Sell Dec 2020

Manipulating Air-Gap Electrospinning To Create Aligned Polymer Nanofiber-Wrapped Glass Microfibers For Cortical Bone Tissue Engineering, Houston R. Linder, Austin A. Glass, Delbert E. Day, Scott A. Sell

Materials Science and Engineering Faculty Research & Creative Works

Osteons are the repeating unit throughout cortical bone, consisting of canals filled with blood and nerve vessels surrounded by concentric lamella of hydroxyapatite-containing collagen fibers, providing mechanical strength. Creating a biodegradable scaffold that mimics the osteon structure is crucial for optimizing cellular infiltration and ultimately the replacement of the scaffold with native cortical bone. In this study, a modified air-gap electrospinning setup was exploited to continuously wrap highly aligned polycaprolactone polymer nanofibers around individual 1393 bioactive glass microfibers, resulting in a synthetic structure similar to osteons. By varying the parameters of the device, scaffolds with polymer fibers wrapped at angles …

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A Bibliometric Survey On Polymer Composites In Energy Storage Applications, Babaji Ghule, Meena Laad Nov 2020

A Bibliometric Survey On Polymer Composites In Energy Storage Applications, Babaji Ghule, Meena Laad

Library Philosophy and Practice (e-journal)

Ceramic polymer composites have gained a significant place in energy storage applications for electrical capacitors due to their distinguished properties. There is a huge demand of capacitors with high energy density, high dielectric strength, negligibly low dielectric loss, light weight, chemically less reactive in energy storage applications. These requirements can be fulfilled by ceramic polymer composites only which exhibit all the above-mentioned characteristics. Considering the huge demand of such capacitors, it has attracted the attention of researchers around the world. The present work attempts to summarise all the research conducted on Polymer Composites for energy storage applications and provides an …

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Study On The Viability Of Preparing Plaster Molds For Rapid Prototyping Of Complex Ceramic Parts Using The Lost Pla Method, Shelton F. Fowler Iv Nov 2020

Study On The Viability Of Preparing Plaster Molds For Rapid Prototyping Of Complex Ceramic Parts Using The Lost Pla Method, Shelton F. Fowler Iv

Honors College Theses

In the field of metal casting, cast parts often require an internal cavity to be made to meet design requirements. Frequently, these interior surfaces are not manufacturable through standard machining processes, and even when possible, they would most likely involve expensive and time-consuming operations. In order to avoid these machining costs, expendable ceramic or sand cores are manufactured and placed into the mold to allow the direct casting of complex internal geometries. This research seeks to use relatively inexpensive plastic 3D printing technology and the lost PLA casting process for the production of low-cost and rapidly producible ceramic cores. A …

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Effects Of Inert Additives On Cyclotrimethylene-Trinitramine (Rdx)/Trinitrotoluene (Tnt) Detonation Parameters To Predict Detonation Synthesis Phase Production, Martin Langenderfer, William Fahrenholtz, Catherine E. Johnson Nov 2020

Effects Of Inert Additives On Cyclotrimethylene-Trinitramine (Rdx)/Trinitrotoluene (Tnt) Detonation Parameters To Predict Detonation Synthesis Phase Production, Martin Langenderfer, William Fahrenholtz, Catherine E. Johnson

Materials Science and Engineering Faculty Research & Creative Works

A methodology was developed to predict pressure and temperature regimes achieved during detonation of RDX/TNT compositions with inert granular inclusions. The predicted pressures and temperatures are used as inputs for thermochemical simulations to design detonation synthesis experiments that utilize shock-induced chemical reactions to produce ceramic nanomaterials. This study computationally assessed the effects of inert spherical sand inclusions and porosity produced by inert additives on the sensitivity of the explosive composition during the shock-to-detonation transition using a limited scope approach through Lee-Tarver ignition and growth modeling. On the continuum scale, the effects of inert additives on pressure generation behind the detonation …

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Interactions Between Dry Vibratable Tundish Linings And Steel Melts, Tyler M. Richards, Ronald J. O'Malley, Jeffrey D. Smith, Todd P. Sander Sep 2020

Interactions Between Dry Vibratable Tundish Linings And Steel Melts, Tyler M. Richards, Ronald J. O'Malley, Jeffrey D. Smith, Todd P. Sander

Materials Science and Engineering Faculty Research & Creative Works

Interactions between two tundish working linings and molten steel were investigated using industrial samples and laboratory testing. Periclase-based dry vibe linings from two production facilities were sampled and examined after casting: one containing 30 wt.% olivine and one without olivine. Cathodoluminescence imaging, secondary electron microscopy, energydispersive spectroscopy and x-ray diffraction analysis were performed to characterize the interactions. An experiment was developed to replicate the conditions found in a production tundish on the laboratory scale. Results comparing interactions observed in laboratory lining tests and commercial lining samples for the two lining materials are presented and discussed.

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Fatigue Of A Sic/Sic Ceramic Composite With An Ytterbium‐Disilicate Environmental Barrier Coating At Elevated Temperature, Marina B. Ruggles-Wrenn, Thaddeus M. Williams Sep 2020

Fatigue Of A Sic/Sic Ceramic Composite With An Ytterbium‐Disilicate Environmental Barrier Coating At Elevated Temperature, Marina B. Ruggles-Wrenn, Thaddeus M. Williams

Faculty Publications

Excerpt: Tension-tension fatigue performance of a SiC/SiC composite with an ytterbium-disilicate environmental barrier coating (EBC) was investigated at 1200°C in air and steam. The composite is reinforced with Hi-Nicalon™ SiC fibers and has a melt-infiltrated matrix processed by chemical vapor infiltration of SiC with subsequent infiltration with SiC particulate slurry and molten silicon. Abtract © American Ceramic Society

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Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor Aug 2020

Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor

Boise State University Theses and Dissertations

The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to …

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International Year Of Glass, Bill Fahrenholtz Jul 2020

International Year Of Glass, Bill Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

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Predicting Effective Fracture Toughness Of Zrb₂-Based Ultra-High Temperature Ceramics By Phase-Field Modeling, Arezoo Emdadi, Jeremy Lee Watts, William Fahrenholtz, Greg Hilmas, Mohsen Asle Zaeem Jul 2020

Predicting Effective Fracture Toughness Of Zrb₂-Based Ultra-High Temperature Ceramics By Phase-Field Modeling, Arezoo Emdadi, Jeremy Lee Watts, William Fahrenholtz, Greg Hilmas, Mohsen Asle Zaeem

Materials Science and Engineering Faculty Research & Creative Works

The effective fracture toughness (EFT) of ZrB2-C ceramics with different engineered microarchitectures was numerically evaluated by phase-field modeling. To verify the model, fibrous monoliths (elongated hexagonal ZrB2-rich cells in a continuous C-rich matrix) with different volume fractions of a C-rich phase were considered. Architectures containing 10 and 30 vol% of C-rich phase showed EFT values about 42% more than that of pure ZrB2. Increasing the C-rich phase to 50 vol%, dropped toughness significantly, which is in agreement with the experimental results. Replacing hexagonal cells with cylindrical, triangular, or square cells of the same cross-sectional …

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Synthesis And Application Of Ceramic Paste For High-Temperature Electronic Packaging, Ardalan Nasiri Jul 2020

Synthesis And Application Of Ceramic Paste For High-Temperature Electronic Packaging, Ardalan Nasiri

Graduate Theses and Dissertations

This dissertation research focused on the synthesis and application of ceramic paste for high-temperature applications. An alumina paste material comprising aluminum dihydric phosphate and alumina powder was developed for high-temperature electronic packaging. Nano aluminum nitride and nano-silica powders were embedded to promote the paste curing process, limit the grain growth, and increase its bond shear strength. The chip-to-substrate bond strength was enhanced and met the MIL-STD requirements for die-attach assembly. Its encapsulation property was improved with fewer cracks compared to similar commercial ceramic encapsulants. The die-attach material and encapsulation properties tested at 500°C showed no defect or additional cracks. Thermal …

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Simultaneous Effects Of Rice Husk Silica And Silicon Carbide Whiskers On The Mechanical Properties And Morphology Of Sodium Geopolymer, Akm Rahman, Chirag Shah, Nihkil Gupta Jun 2020

Simultaneous Effects Of Rice Husk Silica And Silicon Carbide Whiskers On The Mechanical Properties And Morphology Of Sodium Geopolymer, Akm Rahman, Chirag Shah, Nihkil Gupta

Publications and Research

The current research is focused on developing a geopolymer binder using rice husk ash–derived silica nanoparticles. Four types of rice husks were collected directly from various rice fields of Bangladesh in order to evaluate the pozzolanic activity and compatibility of the derived rice husk ashes with precursors of sodium-based geopolymers. Silicon carbide whiskers were introduced into sodium-based geopolymers in order to evaluate the response of silicon carbide whiskers to the interfacial bonding and strength of sodium-based geopolymers along with rice husk ashes. Compression, flexural and short beam shear tests were performed to investigate the synergistic effect of rice husk ashes–derived …

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Prediction Of Flotation Efficiency Of Metal Sulfides Using An Original Hybrid Machine Learning Model, Rachel Cook, Keitumetse Cathrine Monyake, Muhammad Badar Hayat, Aditya Kumar, Lana Alagha Jun 2020

Prediction Of Flotation Efficiency Of Metal Sulfides Using An Original Hybrid Machine Learning Model, Rachel Cook, Keitumetse Cathrine Monyake, Muhammad Badar Hayat, Aditya Kumar, Lana Alagha

Materials Science and Engineering Faculty Research & Creative Works

Froth flotation process is extensively used for selective separation of base metal sulfides from uneconomic mineral resources. Reliable prediction of process outcomes (metal recovery and grade) is vital to ensure peak performance. This work employs an innovative hybrid machine learning (ML) model—constructed by combining the random forest model and the firefly algorithm—to predict froth flotation efficiency of galena and chalcopyrite in relation to various experimental process parameters. The hybrid model's prediction performance was rigorously evaluated and compared against four different standalone ML models. The outcomes of this study illustrate that the hybrid ML model has the prediction ability to process …

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Investigation Of Ceramic Firing Processes For Investment Casting Shell Molds, Leonardo Ken Hoaakua Nakamura, Rileigh Anne Cotter Jun 2020

Investigation Of Ceramic Firing Processes For Investment Casting Shell Molds, Leonardo Ken Hoaakua Nakamura, Rileigh Anne Cotter

Materials Engineering

PCC Structurals aims to improve the quality and consistency of their ceramic mold production for their investment casting processes to decrease product loss figures. Although their current production processes result in acceptable quantities of high-quality molds, a significant percentage of defective molds are produced. These defective molds cause appreciable product loss due to casting defects and mold failure. Available literature dictates that high-quality investment casting molds must exhibit fracture strengths within a desired range in order to perform adequately. However, information regarding specific firing procedures which consistently result in ceramic mold strengths within this range is not readily available. To …

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Tension-Tension Fatigue Behavior Of Nextel™ 720/Alumina-Mullite Ceramic Composite At 1200°C In Air And In Steam, Sarah A. Witzgall Jun 2020

Tension-Tension Fatigue Behavior Of Nextel™ 720/Alumina-Mullite Ceramic Composite At 1200°C In Air And In Steam, Sarah A. Witzgall

Theses and Dissertations

Uniaxial tension-tension fatigue performance of an oxide-oxide continuous fiber ceramic composite was studied at 1200°C in laboratory air and in steam. The composite is reinforced with laminated, 0/90 mullite/alumina (NEXTEL™720) fibers woven in an eight-harness satin weave and has a porous alumina/mullite matrix. There is no interphase between the fiber and matrix. The composite relies on the porous matrix for crack deflection and flaw tolerance. Tension-tension fatigue was examined for maximum stresses of 45 – 136 MPa in air and in steam. To assess the effects of the steam environment on fatigue performance, experimental results obtained in air are compared …

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Empirical Modeling Of Structural Distortions In Perovskite Ceramics, Evan Connor Smith May 2020

Empirical Modeling Of Structural Distortions In Perovskite Ceramics, Evan Connor Smith

Boise State University Theses and Dissertations

Predictive models for composition-structure-property relationships are essential to realizing the full potential of electroceramic materials; however, the electroceramics industry has largely failed to invest in predictive models in favor of simple rules of thumb or expensive, time-consuming trial-and-error methods. Empirically derived predictive models have the potential to significantly improve and guide future research in a more cost-effective and timely manner. It may even be possible to predict some intrinsic properties (e.g., polarization) on the order of a unit cell using only the charge and size of each chemical component. Scientists and researchers may ultimately be able to use …

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Loading Orientation Dependence On The Compressive Response Of Ice-Templated Ceramic-Polymer Composites, Sashanka Akurati, Justine Marin, Dipankar Ghosh Apr 2020

Loading Orientation Dependence On The Compressive Response Of Ice-Templated Ceramic-Polymer Composites, Sashanka Akurati, Justine Marin, Dipankar Ghosh

College of Engineering & Technology (Batten) Posters

Natural materials are made from weak constituents, yet exhibit an excellent synergy of high stiffness, strength, and damage-tolerance. They consist of alternate layers of the hard and soft phases with a complex hierarchical structural organization. The ice-templating technique provides an approach to fabricate multilayered architectures for engineering applications. In this technique, an aqueous ceramic suspension is solidified unidirectionally leading to phase separation into alternating layers of ice-crystals and ceramic particles. Ice-crystals are sublimated by freeze-drying process and resultant ceramic foams are sintered to impart strength. The fabricated sintered ceramic foams contain alternate layers of oriented ceramic lamella walls and pores. …

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Synthesis Of Sic Resin For 3d Printing Of Sic Ceramics By Digital Light Processing, Kevin Zhao, Bai Cui Apr 2020

Synthesis Of Sic Resin For 3d Printing Of Sic Ceramics By Digital Light Processing, Kevin Zhao, Bai Cui

UCARE: Research Products

Silicon carbide (SiC) resin is produced through shear mixing 0.1-1 μm SiC powders with Tethon’s high load Genesis resin base. Resins of varying SiC vol.% were synthesized to test the loading limit of the resin base; 10, 20, and 30 vol.% of SiC were made with the resin base handling the higher loads quite well. Several attempts were made at printing using the Tethon Bison 1000 DLP printer with higher loads of SiC showing better results even with lower intensity UV lights andtimes.

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Development Of B-Type And Multi-Ion Doped Carbonated Hydroxyapatite Bioceramics, Safarzadeh Marjan Apr 2020

Development Of B-Type And Multi-Ion Doped Carbonated Hydroxyapatite Bioceramics, Safarzadeh Marjan

Student Works (2020-2029)

The present research is aimed to investigate the effect of varying the carbonate to phosphate (CO32−/ PO43‒) molar ratios from 0.5 to 5 on the physical and mechanical properties of carbonated hydroxyapatite (CHA) synthesized by a wet chemical method. The sintering was performed under dry carbon dioxide atmosphere at 900 °C to maintain the B-type CHA structure. It was found that increases in CO32−/ PO43‒ ratio was accompanied by an increase in the c/a lattice ratio. The diffraction peaks of the synthesized 0.5-5 CHA powders exhibited a single phase material except for 5CHA which revealed the some minor calcite or …

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Cyclic Regeneration Of Nanostructured Composites For Catalytic Applications, Fatih Dogan Mar 2020

Cyclic Regeneration Of Nanostructured Composites For Catalytic Applications, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

A cermet catalyst material, defining a matrix having interconnected open pores, the matrix selected from the group consisting of YSZ and CGO and defining a substrate, a ceramic coating having a general formula AyBnOx at least partially coating the pores, and a plurality of metal particles A at least partially embedded in the ceramic coating. A is selected from the group consisting of Co, Cu, Ce, Ni, Ti, and combinations thereof and B is selected from the group consisting of Mo, W, Ce, and combinations thereof. When the coating is in a first oxidizing atmosphere …

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Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite With Environmental Barrier Coating At 1200°C In Air And In Steam, Thaddeus M. Williams Mar 2020

Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite With Environmental Barrier Coating At 1200°C In Air And In Steam, Thaddeus M. Williams

Theses and Dissertations

Advanced aerospace applications such as aircraft turbine engine components, hypersonic flight vehicles, and spacecraft reentry thermal protection systems require structural materials that have superior long-term mechanical properties under high temperature, high pressure, and varying environmental factors, such as moisture. Because of their low density, high strength and fracture toughness at high temperatures SiC fiber-reinforced SiC matrix composites are being evaluated for aircraft engine hot-section components. In these applications the composites will be subjected to various types of mechanical loadings at elevated temperatures in oxidizing environments. Because their constituents are intrinsically oxidation-prone, the most significant problem hindering SiC/SiC composites is oxidation …

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