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Materials Science and Engineering Faculty Research & Creative Works

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Full-Text Articles in Materials Science and Engineering

Intragranular Nanocomposite Powders As Building Blocks For Ceramic Nanocomposites, Ryan D. Dempsey, Xiaoqing He, Jonathan A. Scott, David W. Lipke Jan 2023

Intragranular Nanocomposite Powders As Building Blocks For Ceramic Nanocomposites, Ryan D. Dempsey, Xiaoqing He, Jonathan A. Scott, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

A powder-based bottom-up processing scheme is introduced for the production of ceramic nanocomposites. Internal displacement reactions between solid solution powders and metallic reactants proceeding via gaseous intermediates are utilized to generate nanostructured building blocks for the synthesis of ceramic nanocomposites. Subsequent rapid sintering results in ceramic nanocomposites, whose microstructures are inherited from the building blocks. This processing scheme is demonstrated for the production of titanium carbide nanocomposites featuring up to 28 wt.% intragranular tungsten inclusions derived from titanium-tungsten mixed carbide powders. Heat treatment of mixed carbide powders in evacuated ampoules containing titanium sponge and iodine at 1000°C for 24 h …

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High Temperature Dielectric Properties Of Calcium Zirconate, Alan Devoe, Hung Trinh, Fatih Dogan Jan 2023

High Temperature Dielectric Properties Of Calcium Zirconate, Alan Devoe, Hung Trinh, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

The electrical properties of dense, high purity CaZrO3 discs, sintered at 1380°C with and without added ZrO2, were investigated up to 950°C. Dielectric constant, loss tangent, and electrical conductivity were measured from 25 to 725°C, and the real and imaginary impedances were measured between 800 and 950°C by impedance spectroscopy techniques. Dielectric constant increased by 8% above 300°C and loss tangent increased from.1% at 25°C to ∼2% above 300°C. Activation energy of electrical conductivity determined between 300°C and 950°C by alternative current (AC) and direct current (DC) measurements. These results indicate that CaZrO3 could be a useful dielectric material for …

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Synthesis, Densification, And Cation Inversion In High Entropy (Co,Cu,Mg,Ni,Zn)Al2o4 Spinel, Cole A. Corlett, Nina Obradovic, Jeremy Lee Watts, Eric W. Bohannan, William Fahrenholtz Jan 2023

Synthesis, Densification, And Cation Inversion In High Entropy (Co,Cu,Mg,Ni,Zn)Al2o4 Spinel, Cole A. Corlett, Nina Obradovic, Jeremy Lee Watts, Eric W. Bohannan, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co0.2Cu0.2Mg0.2Ni0.2 Zn0.2)Al2O4. Each composition was reacted to form a single phase, but analysis of X-ray diffraction patterns revealed differences in cation site occupancy with the high-entropy spinel being nearly fully normal. Densification behavior was investigated and showed that fully dense ceramics could be produced by hot pressing at temperatures as low as 1375°C for all compositions. Vickers' hardness values were at least 10 GPa for all compositions. The …

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Additive Manufacturing Of Sic-Sialon Refractory With Excellent Properties By Direct Ink Writing, Ruoyu Chen, Saisai Li, Xinxin Jin, Haiming Wen Jan 2023

Additive Manufacturing Of Sic-Sialon Refractory With Excellent Properties By Direct Ink Writing, Ruoyu Chen, Saisai Li, Xinxin Jin, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Additive manufacturing of SiC-Sialon refractory with complex geometries was achieved using direct ink writing processes, followed by pressure less sintering under nitrogen. The effects of particle size of SiC powders, solid content of slurries and additives on the rheology, thixotropy and viscoelasticity of ceramic slurries were investigated. The optimal slurry with a high solid content was composed of 81 wt% SiC (3.5 µm+0.65 µm), Al2O3 and SiO2 powders, 0.2 wt% dispersant, and 2.8 wt% binder. Furthermore, the accuracy of the structure of specimens was improved via adjustment of the printing parameters, including nozzle size, extrusion pressure, and layer height. The …

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Reduction Of Iron-Ore Pellets Using Different Gas Mixtures And Temperatures, Yuri Korobeinikov, Amogh Meshram, Christopher Harris, Olexandr Kovtun, Joe Govro, Ronald J. O'Malley, Olena Volkova, Seetharaman Sridhar Jan 2023

Reduction Of Iron-Ore Pellets Using Different Gas Mixtures And Temperatures, Yuri Korobeinikov, Amogh Meshram, Christopher Harris, Olexandr Kovtun, Joe Govro, Ronald J. O'Malley, Olena Volkova, Seetharaman Sridhar

Materials Science and Engineering Faculty Research & Creative Works

Direct reduction of iron ore (DRI) is gaining an increased attention due to the growing need to decarbonize industrial processes. The current industrial DRI processes are performed using reformed natural gas, which results in CO2 emission, although it is less than carbothermic reduction in the blast furnace. Carbon-free reduction may be realized through the utilization of green H2 as a reducing agent, in place of natural gas. Herein, the effects of various gas mixtures and temperature on the reduction kinetics of the hematite iron-ore pellets are focused on in this work. Pellets are reduced at 700, 800, 850, …

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Performance Evaluation Of Composite Sandwich Structures With Additively Manufactured Aluminum Honeycomb Cores With Increased Bonding Surface Area, M. Rangapuram, S. K. Dasari, Joseph William Newkirk, K. Chandrashekhara, H. Misak, P. R. Toivonen, D. Klenosky, T. Unruh, J. Sam Jan 2023

Performance Evaluation Of Composite Sandwich Structures With Additively Manufactured Aluminum Honeycomb Cores With Increased Bonding Surface Area, M. Rangapuram, S. K. Dasari, Joseph William Newkirk, K. Chandrashekhara, H. Misak, P. R. Toivonen, D. Klenosky, T. Unruh, J. Sam

Materials Science and Engineering Faculty Research & Creative Works

Modern aerostructures, including wings and fuselages, increasingly feature sandwich structures due to their high-energy absorption, low weight, and high flexural stiffness. The face sheet of these sandwich structures are typically thin composite laminates with interior honeycombs made of Nomex or aluminum. Standard cores are structurally efficient, but their design cannot be varied throughout the structure. With additive manufacturing (AM) technology, these core geometries can be altered to meet the design requirements that are not met in standard honeycomb cores. This study used a modified aluminum honeycomb core, with increased surface area on the top and bottom, as the core material …

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Morphological And Structural Characterization Of Mgal2o4 Spinel, Nina Obradović, Suzana Filipović, William Fahrenholtz, Bojan A. Marinkovic, Jelena Rogan, Steva Lević, Antonije Đorđević, Vladimir B. Pavlović Jan 2023

Morphological And Structural Characterization Of Mgal2o4 Spinel, Nina Obradović, Suzana Filipović, William Fahrenholtz, Bojan A. Marinkovic, Jelena Rogan, Steva Lević, Antonije Đorđević, Vladimir B. Pavlović

Materials Science and Engineering Faculty Research & Creative Works

Magnesium aluminate has the spinel structure along with good mechanical, chemical, and thermal properties. Magnesium aluminate has a wide range of applications including refractory ceramics, optically transparent ceramic windows, and armors. Its low dielectric permeability and low loss tangent enable its applications for integrated electronic devices, as well. In this paper, MgO and Al2O3 powders were mixed in a one-to-one molar ratio and calcined at temperatures ranging from 1500 to 1800o C to produce phase pure spinel. Thereafter, pellets were crushed and treated in a planetary ball mill for 60 min to obtain a fine powder. All …

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Antioxidant Theranostic Copolymer-Mediated Reduction In Oxidative Stress Following Traumatic Brain Injury Improves Outcome In A Mouse Model, Aria W. Tarudji, Connor C. Gee, Hunter A. Miller, Rylie Steffen, Evan T. Curtis, Aaron M. Priester, Anthony J. Convertine, Forrest M. Kievit Jan 2023

Antioxidant Theranostic Copolymer-Mediated Reduction In Oxidative Stress Following Traumatic Brain Injury Improves Outcome In A Mouse Model, Aria W. Tarudji, Connor C. Gee, Hunter A. Miller, Rylie Steffen, Evan T. Curtis, Aaron M. Priester, Anthony J. Convertine, Forrest M. Kievit

Materials Science and Engineering Faculty Research & Creative Works

Following a traumatic brain injury (TBI), excess reactive oxygen species (ROS) and lipid peroxidation products (LPOx) are generated and lead to secondary injury beyond the primary insult. A major limitation of current treatments is poor target engagement, which has prevented success in clinical trials. Thus, nanoparticle-based treatments have received recent attention because of their ability to increase accumulation and retention in damaged brain. Theranostic neuroprotective copolymers (NPC3) containing thiol functional groups can neutralize ROS and LPOx. Immediate administration of NPC3 following injury in a controlled cortical impact (CCI) mouse model provides a therapeutic window in reducing ROS levels at 2.08–20.83 …

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The Effect Of Crystal Anisotropy On Fracture Toughness And Strength Of Zrb2 Microcantilevers, Tamás Csanádi, Ahmad Azizpour, Marek Vojtko, William Fahrenholtz Jan 2023

The Effect Of Crystal Anisotropy On Fracture Toughness And Strength Of Zrb2 Microcantilevers, Tamás Csanádi, Ahmad Azizpour, Marek Vojtko, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The influence of crystal anisotropy on the micromechanical properties of ceramic grains plays an important role in the design of the macromechanical performance of bulk polycrystalline samples. To this end, the effect of crystal orientation on fracture toughness and strength was investigated by microcantilever bending experiments combined with finite element method (FEM) simulations in grains of a polycrystalline ZrB2 sample. The sample was prepared by hot pressing and the crystal orientations were determined by electron backscatter diffraction after careful surface preparation. The bending tests were carried out on notched and unnotched microcantilevers cut from specific grains along the prismatic (⊥ …

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Final-Stage Densification Kinetics Of Direct Current–Sintered Zrb2, Austin D. Stanfield, Steven M. Smith, Suzana Filipović, Nina Obradović, Vladimir Buljak, Gregory E. Hilmas, William Fahrenholtz Jan 2023

Final-Stage Densification Kinetics Of Direct Current–Sintered Zrb2, Austin D. Stanfield, Steven M. Smith, Suzana Filipović, Nina Obradović, Vladimir Buljak, Gregory E. Hilmas, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to …

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Effect Of Mechanical Activation On Carbothermal Synthesis And Densification Of Zrc, Nina Obradović, Lun Feng, Suzana Filipović, Miljana Mirković, Darko Kosanović, Jelena Rogan, William Fahrenholtz Jan 2023

Effect Of Mechanical Activation On Carbothermal Synthesis And Densification Of Zrc, Nina Obradović, Lun Feng, Suzana Filipović, Miljana Mirković, Darko Kosanović, Jelena Rogan, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled …

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Additive Manufacturing Of (Mgconicuzn)O High-Entropy Oxide Using A 3d Extrusion Technique And Oxide Precursors, Ruoyu Chen, Saisai Li, Qingfeng Yan, Haiming Wen Jan 2023

Additive Manufacturing Of (Mgconicuzn)O High-Entropy Oxide Using A 3d Extrusion Technique And Oxide Precursors, Ruoyu Chen, Saisai Li, Qingfeng Yan, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

This report presents an additive manufacturing approach, for the first time, to producing high-entropy oxides (HEOs) using a 3D extrusion-based technique with oxide precursors. The precursors were prepared by a wet chemical method from sulfates. Additives were utilized to optimize the rheological properties of the printing inks with these precursors, and the properties of the printed HEOs were improved by increasing the solid content of the inks. When ink with a solid content of 78 wt% was used for printing, the resulting HEO exhibited a relative density of 92% and a high dielectric constant after undergoing pressure less sintering at …

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High-Temperature Interactions Between Titanium Alloys And Strontium Zirconate Refractories, R. Sharon Uwanyuze, Baris Yavas, Jiyao Zhang, Janos E. Kanyo, Lesley D. Frame, Rainer J. Hebert, Stefan Schafföner, S. Pamir Alpay Jan 2023

High-Temperature Interactions Between Titanium Alloys And Strontium Zirconate Refractories, R. Sharon Uwanyuze, Baris Yavas, Jiyao Zhang, Janos E. Kanyo, Lesley D. Frame, Rainer J. Hebert, Stefan Schafföner, S. Pamir Alpay

Materials Science and Engineering Faculty Research & Creative Works

We investigated interactions between Ti6Al4V alloys and strontium zirconate (SrZrO3) ceramic to assess its potential as a refractory mold material in investment casting. We developed a robust yet simple procedure to examine both the liquid–solid and solid–solid interactions using pellets in drop casting and diffusion couple methods. Reaction layers were characterized using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray diffraction (XRD). The results were compared to alumina (Al2O3) which is still a common refractory ceramic for molds in investment casting. Our findings indicate that Ti6Al4V surfaces in contact with …

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Strength Retention Of Single-Phase High-Entropy Diboride Ceramics Up To 2000°C, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Yue Zhou, Jincheng Bai Jan 2023

Strength Retention Of Single-Phase High-Entropy Diboride Ceramics Up To 2000°C, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Yue Zhou, Jincheng Bai

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties of single-phase (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)B2 ceramics with high purity were investigated. The resulting ceramics had relative density greater than 99%, and an average grain size of 4.3 ± 1.6 μm. At room temperature (RT), the Vickers hardness was 25.2 ± 0.6 GPa at a load of 0.49 N, Young's modulus was 551 ± 7 GPa, fracture toughness was 4.5 ± 0.4 MPa m1/2, and flexural strength was 507 ± 10 MPa. Flexural strength increased by more than 50% from 507 ± 10 MPa at RT to 776 ± …

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Improving Strength And Microstructure Of Sic Reticulated Porous Ceramic Through In-Situ Generation Of Sic Whiskers Within Hollow Voids, Ruoyu Chen, Kunshi Xie, Haipeng Zhu, Qun He, Saisai Li, Haiming Wen Jan 2023

Improving Strength And Microstructure Of Sic Reticulated Porous Ceramic Through In-Situ Generation Of Sic Whiskers Within Hollow Voids, Ruoyu Chen, Kunshi Xie, Haipeng Zhu, Qun He, Saisai Li, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

SiC Reticulated Porous Ceramic with Excellent Strength and High-Density Ceramic Struts Was Successfully Prepared using the Polymer Replica Method, Followed by Pressureless Sintering under a Buried Charcoal Atmosphere. First, a Polyurethane (PU) Template Was Coated with a Si Slurry and Then a SiC-Containing Slurry, and Subsequently Heated under the Buried Charcoal Atmosphere. to Ensure Excellent Coating Ability of the Slurries, the Viscosity, Thixotropy, and Yield Stresses of the Si Slurry Were Optimized by Adjusting the Content of the Thickening Agent. during Heating, Si in the Coating Layer Reacted with the Residual C and CO Gas from the PU Template and …

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Phenomenological Analysis Of Surface Degradation Of Metallic Materials In Extreme Environment, Simon N. Lekakh, Oleg Neroslavsky Jan 2023

Phenomenological Analysis Of Surface Degradation Of Metallic Materials In Extreme Environment, Simon N. Lekakh, Oleg Neroslavsky

Materials Science and Engineering Faculty Research & Creative Works

The resistance to surface degradation in metallic alloys plays an important role for the lifetime of the components working in harsh environments. The mechanisms involved in degradation of metallic surface in a high-temperature aggressive gaseous atmosphere include the following: forming adherent to the surface multiphase oxide layer, partial spallation, and possible vaporization of formed compounds. The governing equation, which describes a parabolic growth of adherent layer, time-dependent vaporization, and cross-linked to instantaneous thickness of adherent layer spallation rate, was suggested and analyzed. The several relationships between the kinetic constants were defined from analysis of the governing equation. Design of routes …

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Real-Time Air Gap And Thickness Measurement Of Continuous Caster Mold Flux By Extrinsic Fabry-Perot Interferometer, Abhishek Prakash Hungund, Hanok Tekle, Bohong Zhang, Ronald J. O'Malley, Jeffrey D. Smith, Rex E. Gerald, Jie Huang Jan 2023

Real-Time Air Gap And Thickness Measurement Of Continuous Caster Mold Flux By Extrinsic Fabry-Perot Interferometer, Abhishek Prakash Hungund, Hanok Tekle, Bohong Zhang, Ronald J. O'Malley, Jeffrey D. Smith, Rex E. Gerald, Jie Huang

Materials Science and Engineering Faculty Research & Creative Works

Mold Flux plays a critical role in continuous casting of steel. Along with many other functions, the mold flux in the gap between the solidifying steel shell and the mold serves as a medium for controlling heat transfer and as a barrier to prevent shell sticking to the mold. This manuscript introduces a novel method of monitoring the structural features of a mold flux film in real-time in a simulated mold gap. A 3-part stainless-steel mold was designed with a 2 mm, 4 mm and, 6 mm step profile to contain mold flux films of varying thickness. An Extrinsic Fabry-Perot …

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Effect Of Annealing Time On Texture Evolution Of Fe–3.4 Wt% Si Nonoriented Electrical Steel, Yizhou Du, Ronald J. O'Malley, Mario F. Buchely, Paul Kelly Jan 2023

Effect Of Annealing Time On Texture Evolution Of Fe–3.4 Wt% Si Nonoriented Electrical Steel, Yizhou Du, Ronald J. O'Malley, Mario F. Buchely, Paul Kelly

Materials Science and Engineering Faculty Research & Creative Works

Herein, the Effect of Annealing Time on the Texture Evolution in Fe–3.4 Wt.% Si Non-Oriented Electrical Steel is Investigated. Strip Samples Are Cast using a Vacuum Sampling Method, Which Simulate the Solidification Conditions of an Industrial Twin Roll Thin Strip Casting (TRSC) Process. As-Cast Samples with Different Carbon and Sulfur (C&S) Levels Are Hot Rolled (HR) with Varying Levels of Hot Deformation, Cold Rolled (CR) to 0.35 Mm Thickness, and Then Annealed at 1050 °C for Different Holding Times (1, 6, 24 H). to Fe–3.4 Wt.% Si Non oriented Electrical Steel, the Observed Texture Evolution Can Be Divided into Different …

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Advancing Aluminum Casting Optimization With Real-Time Temperature And Gap Measurements Using Optical Fiber Sensors At The Metal-Mold Interface, Bohong Zhang, Abhishek Prakash Hungund, Dinesh Reddy Alla, Deva Prasaad Neelakandan, Muhammad Roman, Ronald J. O'Malley, Laura Bartlett, Rex E. Gerald, Jie Huang Jan 2023

Advancing Aluminum Casting Optimization With Real-Time Temperature And Gap Measurements Using Optical Fiber Sensors At The Metal-Mold Interface, Bohong Zhang, Abhishek Prakash Hungund, Dinesh Reddy Alla, Deva Prasaad Neelakandan, Muhammad Roman, Ronald J. O'Malley, Laura Bartlett, Rex E. Gerald, Jie Huang

Materials Science and Engineering Faculty Research & Creative Works

Accurate measurement of interfacial heat transfer during casting solidification is crucial for optimizing metal solidification processes. The gap between the mold wall and the casting surface plays a significant role in heat transfer and cooling rates. In this study, two innovative fiber-optic sensors are employed to measure real-time mold gaps and thermal profiles during the solidification of A356 aluminum in a permanent mold casting. The experimental setup consists of a specially designed mold system made of unheated, uncoated tool steel, which facilitates easy installation of the fiber-optic sensors. An Extrinsic Fabry-Perot interferometric (EFPI) sensor is utilized to monitor the evolving …

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Impact Of Alumina-Based Binder On Formation Of Dense Strontium Zirconate Ceramics, Janos E. Kanyo, R. Sharon Uwanyuze, Jiyao Zhang, Rainer Hebert, Stefan Schafföner, Lesley Frame Jan 2023

Impact Of Alumina-Based Binder On Formation Of Dense Strontium Zirconate Ceramics, Janos E. Kanyo, R. Sharon Uwanyuze, Jiyao Zhang, Rainer Hebert, Stefan Schafföner, Lesley Frame

Materials Science and Engineering Faculty Research & Creative Works

Strontium zirconate (SrZrO3) is a technical ceramic with potential for refractory applications due to its chemical stability at high temperatures, high melting temperature, and favorable thermal expansion coefficient. Practical use of SrZrO3 is limited by poor mechanical strength relative to ceramics such as alumina (Al2O3). Sintering of SrZrO3 with a hydratable Al2O3 binder is investigated as a method for improving mechanical performance. Density, phase composition, thermomechanical properties, and chemical stability in contact with alloys up to 1350 °C are considered. Results are compared with SrZrO3 samples formed using a traditional polyvinyl alcohol (PVA) binder. SrZrO3 reacts with alumina during sintering …

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Residual Stress Distribution, Distortion, And Crack Initiation In Conventional And Intensive Quench Practices, Kingsley Tochukwu Amatanweze, Mario F. Buchely, Viraj Ashok Athavale, Laura Bartlett, Ronald J. O'Malley, Toshi Suzuki Jan 2023

Residual Stress Distribution, Distortion, And Crack Initiation In Conventional And Intensive Quench Practices, Kingsley Tochukwu Amatanweze, Mario F. Buchely, Viraj Ashok Athavale, Laura Bartlett, Ronald J. O'Malley, Toshi Suzuki

Materials Science and Engineering Faculty Research & Creative Works

This study evaluates the effect of two different quench practices on distortion, sensitivity to quench cracking, development and distribution of residual stress, microstructural uniformity, and hardenability of standardized test castings. Navy C-rings made of AISI 4340 were quenched in this experiment. Some rings were quenched in a conventional draft tube immersion quench bath, and others were quenched in an intensive quench spray system to compare with the results from the conventional immersion quench bath. The rings were measured with a coordinate measuring machine, for distortion and flatness, before and after quenching. Hardness profiles of the quenched rings showed through hardness …

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Microstructure Evolution And Austenitic Grain Refinement Of Ti-Modified High Mn Steels During Solution Annealing Heat Treatment, Abhinav Karanam, Arnab Sarkar, Erik Nenzen, Viraj Ashok Athavale, Mark Watson, Laura Nicole Bartlett, Lukas Bichler Jan 2023

Microstructure Evolution And Austenitic Grain Refinement Of Ti-Modified High Mn Steels During Solution Annealing Heat Treatment, Abhinav Karanam, Arnab Sarkar, Erik Nenzen, Viraj Ashok Athavale, Mark Watson, Laura Nicole Bartlett, Lukas Bichler

Materials Science and Engineering Faculty Research & Creative Works

Austenitic high manganese (Mn) steels are often used in harsh environments due to their high toughness and wear resistance. Heat treatments are performed to engineer the microstructure of the steels and optimize their performance for the desired service conditions. This study investigated the effect of titanium (Ti) and heat treatment on the microstructure of cast high Mn steel (HMS) alloys. The results reveal that Ti addition contributed to grain refinement in the as cast and heat-treated conditions. In-situ observation of microstructure evolution up to 1125 °C confirmed the stability of precipitated TiC particles, while revealing a new mechanism of grain …

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A Fiber-Optic Sensor-Embedded And Machine Learning Assisted Smart Helmet For Multi-Variable Blunt Force Impact Sensing In Real Time, Yiyang Zhuang, Taihao Han, Qingbo Yang, Ryan O'Malley, Aditya Kumar, Rex E. Gerald, Jie Huang Dec 2022

A Fiber-Optic Sensor-Embedded And Machine Learning Assisted Smart Helmet For Multi-Variable Blunt Force Impact Sensing In Real Time, Yiyang Zhuang, Taihao Han, Qingbo Yang, Ryan O'Malley, Aditya Kumar, Rex E. Gerald, Jie Huang

Materials Science and Engineering Faculty Research & Creative Works

Early on-site diagnosis of mild traumatic brain injury (mTBI) will provide the best guidance for clinical practice. However, existing methods and sensors cannot provide sufficiently detailed physical information related to the blunt force impact. In the present work, a smart helmet with a single embedded fiber Bragg grating (FBG) sensor is developed, which can monitor complex blunt force impact events in real time under both wired and wireless modes. The transient oscillatory signal "fingerprint" can specifically reflect the impact-caused physical deformation of the local helmet structure. By combination with machine learning algorithms, the unknown transient impact can be recognized quickly …

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Local Structure In High-Entropy Transition Metal Diborides, Mattia Gaboardi, Frederic Monteverde, Federico Saraga, Giuliana Aquilanti, Lun Feng, William Fahrenholtz, Gregory Hilmas Oct 2022

Local Structure In High-Entropy Transition Metal Diborides, Mattia Gaboardi, Frederic Monteverde, Federico Saraga, Giuliana Aquilanti, Lun Feng, William Fahrenholtz, Gregory Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Studies on high-entropy materials often speculate about the effects of lattice distortion and disorder on characteristics such as hardness, thermal expansion, and electronic properties. Notwithstanding the ongoing race to discover new compositions, investigations of the local structure at the atomic level remain sparse at best. Additionally, assessments of the homogeneity of the distribution of metals within the lattice sites are often restricted to techniques such as energy dispersive spectroscopy which might lead to an inaccurate picture of the bulk material. Herein, we report an extensive and systematic study of a class of emerging high-entropy ceramics that uses a combination of …

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Effect Of Cu Additions On Scale Structure And Descaling Efficiency Of Low C Steel Reheated In A Combustion Gas Atmosphere, Richard Osei, Simon Lekakh, Ronald J. O'Malley Oct 2022

Effect Of Cu Additions On Scale Structure And Descaling Efficiency Of Low C Steel Reheated In A Combustion Gas Atmosphere, Richard Osei, Simon Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Modern EAF steelmaking employs scrap as its primary source of raw material. Different sources of scrap have varying levels of residuals, which can negatively influence product properties, performance, and surface quality. The presence of some residuals, such as Cu and Ni in controlled quantities, can also positively impact steel performance for some applications. It is also well known that interactions between residuals and alloying elements in steel can modify the structure of scale formed during slab reheating prior to hot rolling. These changes in the scale structure can influence scale removability. In this study, the effect of varying Cu concentrations …

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Fusion Welding Of Refractory Metals And Zrb2-Sic-Zrc Ceramics, Jecee D. Jarman, William Fahrenholtz, Greg Hilmas, Jeremy Lee Watts, Tieshu Huang Oct 2022

Fusion Welding Of Refractory Metals And Zrb2-Sic-Zrc Ceramics, Jecee D. Jarman, William Fahrenholtz, Greg Hilmas, Jeremy Lee Watts, Tieshu Huang

Materials Science and Engineering Faculty Research & Creative Works

Molybdenum and a molybdenum alloy were fusion welded to ZrB2-based ceramics to determine if the electrical and thermal properties of the metals and ceramics affected their weldability. Commercial ceramic powders were hot pressed, machined into coupons, and preheated to 1600 °C before joining the ceramics to commercial metals using plasma arc welding. Weldability varied as indicated by the range of porosity observed within the fusion zones. Measured thermal and electrical properties appeared to have little to no effect on the weldability of metal-ceramic welds despite the large range of values measured across each property. Differences in melting temperatures between metal …

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Stochastic Model For High Temperature Oxidation Of Cr–Ni Austenitic Steels Assisted By Spallation, Simon N. Lekakh, Oleg Neroslavsky, Mei Li, Larry Godlevski Oct 2022

Stochastic Model For High Temperature Oxidation Of Cr–Ni Austenitic Steels Assisted By Spallation, Simon N. Lekakh, Oleg Neroslavsky, Mei Li, Larry Godlevski

Materials Science and Engineering Faculty Research & Creative Works

Cr–Ni austenitic steels offer significant high temperature corrosion protection by forming a surface oxide layer. However, above critical service conditions (temperature, atmosphere, thermal cycling), oxidized surface can experience intensive degradation because of scale spallation, which could be detrimental to the in-service life. To predict the effect of scale spallation on oxidation kinetics, a simulation was implemented using a stochastic model. The model considers topological parameters and intensity of spallation which can occur, while delivering a true oxidation constant. The experimental procedure identified the amount of formed spalled scale and topology of spallation based on the use of element mapping of …

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Hanford Low-Activity Waste Glass Composition-Temperature-Melt Viscosity Relationships, Alejandro Heredia-Langner, Vivianaluxa Gervasio, Scott K. Cooley, Charmayne E. Lonergan, Dong Sang Kim, Albert A. Kruger, John D. Vienna Oct 2022

Hanford Low-Activity Waste Glass Composition-Temperature-Melt Viscosity Relationships, Alejandro Heredia-Langner, Vivianaluxa Gervasio, Scott K. Cooley, Charmayne E. Lonergan, Dong Sang Kim, Albert A. Kruger, John D. Vienna

Materials Science and Engineering Faculty Research & Creative Works

This study developed a model for predicting viscosity of alkali-alumino-borosilicate glass melts as functions of composition and temperature. The model is based on a total of 3935 viscosity-temperature data from 574 glasses with viscosity values ranging from 2.53 to 7260 Poise (P) in the temperature range of 900–1260°C. Several different model forms were surveyed, including those based on Arrhenius, Vogel-Fulcher-Tammann, Avramov-Milchev, and Mauro-Yue-Ellison-Gupta-Allen. For each of these models, combinations of the temperature-independent parameters were fitted to composition. It was found that generally fitting more than one temperature-independent parameter as functions of composition resulted in overfitting. The Avramov-Milchev-based model was found …

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Study Of Asymptotic Velocity In The Bondi–Hoyle Accretion Flows In The Domain Of Kerr And 4-D Einstein–Gauss–Bonnet Gravities, Orhan Donmez, Fatih Dogan, Tuba Sahin Sep 2022

Study Of Asymptotic Velocity In The Bondi–Hoyle Accretion Flows In The Domain Of Kerr And 4-D Einstein–Gauss–Bonnet Gravities, Orhan Donmez, Fatih Dogan, Tuba Sahin

Materials Science and Engineering Faculty Research & Creative Works

Understanding the physical structures of the accreted matter very close to a black hole in quasars and active galactic nucleus (AGN) is an important milestone to constrain the activities occurring in their centers. In this paper, we numerically investigate the effects of the asymptotic velocities on the physical structures of the accretion disk around the Kerr and Einstein–Gauss–Bonnet (EGB) rapidly rotating black holes. The Bondi–Hoyle accretion is considered with a falling gas towards the black hole in an upstream region of the computational domain. Shock cones are naturally formed in the downstream part of the flow around both black holes. …

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Effect Of Rolling Process On Magnetic Properties Of Fe-3.3 Wt% Si Non-Oriented Electrical Steel, Yizhou Du, Ronald J. O'Malley, Mario F. Buchely, Paul Kelly Sep 2022

Effect Of Rolling Process On Magnetic Properties Of Fe-3.3 Wt% Si Non-Oriented Electrical Steel, Yizhou Du, Ronald J. O'Malley, Mario F. Buchely, Paul Kelly

Materials Science and Engineering Faculty Research & Creative Works

In this study, the influence of the rolling process on magnetic properties of Fe-3.3 wt% Si non-oriented electrical steel was investigated. The strip samples were cast using a high solidification cooling rate vacuum sampling method to simulate the solidification conditions of the industrial twin roll thin strip casting (TRSC) process. As-cast samples were subjected to various thermo-mechanical processing routes with different levels of hot-rolling (HR) and cold-rolling (CR). The influence of carbon and sulfur (C&S) contents in the steel were also investigated. Core loss (P1.5/50, P1.5/60, P1.0/50, P1.0/60) and magnetic induction (B25, B50) of the final annealed strip samples were …

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