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Materials Science and Engineering Faculty Research & Creative Works

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Full-Text Articles in Materials Science and Engineering

Detonation Synthesis Of Nanoscale Silicon Carbide From Elemental Silicon, Martin J. Langenderfer, Yue Zhou, Jeremy Lee Watts, William Fahrenholtz, Catherine E. Johnson Feb 2022

Detonation Synthesis Of Nanoscale Silicon Carbide From Elemental Silicon, Martin J. Langenderfer, Yue Zhou, Jeremy Lee Watts, William Fahrenholtz, Catherine E. Johnson

Materials Science and Engineering Faculty Research & Creative Works

Direct reaction of precursors with the products of detonation remains an underexplored area in the ever-growing body of detonation synthesis literature. This study demonstrated the synthesis of silicon carbide during detonation by reaction of elemental silicon with carbon products formed from detonation of RDX/TNT mixtures. Continuum scale simulation of the detonation showed that energy transfer by the detonation wave was completed within 2–9 μs depending on location of measurement within the detonating explosive charge. The simulated environment in the detonation product flow beyond the Chapman-Jouguet condition where pressure approaches 27 GPa and temperatures reach 3300 K was thermodynamically suitable for …

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The Effect Of Sodium Polymethacrylate On The Rheology Of The Positive Paste And Performance Of The Lead-Acid Battery, Julian Kosacki, Dimitri Feys, Fatih Dogan Feb 2022

The Effect Of Sodium Polymethacrylate On The Rheology Of The Positive Paste And Performance Of The Lead-Acid Battery, Julian Kosacki, Dimitri Feys, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

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Nodule Formation On Copper Electrodeposits In The Rotating Cylinder Hull Cell, Joseph Bauer, Michael S. Moats Feb 2022

Nodule Formation On Copper Electrodeposits In The Rotating Cylinder Hull Cell, Joseph Bauer, Michael S. Moats

Materials Science and Engineering Faculty Research & Creative Works

Nodulation formation during the electrolytic production of high-purity copper can lead to impurity entrapment and/or increased energy consumption. The rotating cylinder Hull cell (RCHC) was used to study copper nodule formation under mass transport conditions similar to industrial electrolytic copper production. The main advantage of the RCHC is that a wide range of current densities can be produced in a single experiment with well-defined mass transfer conditions. Visible nodule formation was observed at current densities greater than 250 A/m2, which is an iavg/iL ratio of 0.30 for a simulated conventional electrowinning cell. Statistical analysis was also performed using the Weibull …

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Fundamental Effects Of Al And Ta On Microstructure And Phase Transformations In The Al–Cr–Mo–Ta–Ti Refractory Complex Concentrated Alloy System, Austin E. Mann, Joseph William Newkirk Jan 2022

Fundamental Effects Of Al And Ta On Microstructure And Phase Transformations In The Al–Cr–Mo–Ta–Ti Refractory Complex Concentrated Alloy System, Austin E. Mann, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

The effect of aluminum and tantalum concentrations on a refractory metal complex concentrated alloy is reported, particularly with respect to their effect on microstructure and phase composition of the alloy in cast and annealed form. Alloys with an equiatomic composition, (AlCrMoTaTi), an aluminum-lean composition (Al0.75CrMoTaTi), and a tantalum-lean composition (AlCrMoTa0.75Ti) are produced via arc melting. The alloys exhibit multiphase structures, confirmed by X-ray diffraction, microstructural characterization, and thermal analysis. The minor off-equiatomic adjustments of aluminum and tantalum in this alloy system did not drastically alter the prevalence of the Cr–Ta-based Laves phase. Correlations between thermodynamic predictions and observed phase transformations …

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The Role Of Microstructure On High-Temperature Oxidation Behavior Of Hafnium Carbide, Jonathan A. Scott, Xiaoqing He, David W. Lipke Jan 2022

The Role Of Microstructure On High-Temperature Oxidation Behavior Of Hafnium Carbide, Jonathan A. Scott, Xiaoqing He, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Microstructure development of the products formed upon oxidation of hafnium carbide (HfCx, x = 0.65, 0.81, or 0.94) at 1300°C and 0.8 mbar oxygen pressure was investigated using Raman spectroscopy, X-ray diffraction, electron microscopy, and electron energy-loss spectroscopy. For all specimens a multilayered oxide scale was observed featuring an outermost porous hafnia layer and an interlayer adjacent to the parent carbide containing hafnia interspersed with carbon. The outermost hafnia features coarse pores presumably formed during initial stages of oxidation to allow rapidly evolving gaseous products to escape from the oxidation front. As the oxidation scale thickens, diffusional resistance results in …

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Effect Of Spallation On Oxidation Kinetics Of Heat-Resistant Cr–Ni Austenitic Steels On Air And Combustion Atmosphere, Simon N. Lekakh, Oleg Neroslavsky, Mei Li, Larry Godlewski, Wenhui Zhu Jan 2022

Effect Of Spallation On Oxidation Kinetics Of Heat-Resistant Cr–Ni Austenitic Steels On Air And Combustion Atmosphere, Simon N. Lekakh, Oleg Neroslavsky, Mei Li, Larry Godlewski, Wenhui Zhu

Materials Science and Engineering Faculty Research & Creative Works

Thin-walled castings made from Cr–Ni austenitic steels offer a combination of light weight of a near-net component with significant high temperature corrosion protection by forming a surface oxide layer. However, above critical service conditions (temperature, atmosphere, thermal cycling), oxidized surface can result in intensive surface degradation due to scale spallation. Scale spallation can decrease the wall thickness which could be detrimental to the in-service life of thin-walled castings. Experiments and stochastic simulations of spallation assisted oxidation were performed with three cast austenitic heat-resistant steels having different Cr–Ni concentrations at temperatures between 900 and 1000 ℃ on air and water vapor …

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On The Effect Of Hot Rolling On Inclusion Size And Distribution In A Cast Aisi 1070 Steel Railroad Wheel, Jacob M. Summers, Soumava Chakraborty, Laura Bartlett, Ronald J. O'Malley, Mario F. Buchely, Richard Pilon Jan 2022

On The Effect Of Hot Rolling On Inclusion Size And Distribution In A Cast Aisi 1070 Steel Railroad Wheel, Jacob M. Summers, Soumava Chakraborty, Laura Bartlett, Ronald J. O'Malley, Mario F. Buchely, Richard Pilon

Materials Science and Engineering Faculty Research & Creative Works

The goal of this work is to examine the effect of hot deformation on shrinkage porosity and nonmetallic inclusions in an AISI 1070 grade steel industrially produced wheel casting. Steel cleanliness is an important consideration as it influences the mechanical properties of the final product. A high density of porosity and inclusions have been shown to be detrimental for mechanical properties, especially during hot rolling. Using a laboratory-scale rolling mill, cast preforms were subjected to a 66% cumulative reduction to determine the effect of thermomechanical processing on void closure and inclusions that may produce anisotropy in mechanical properties. Quantitative automated …

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The Effects Of Mixing Multi-Component Hlw Glasses On Spinel Crystal Size, C. (Charmayne) E. Lonergan, J. Rice, C. Skidmore, M. J. Schweiger, P. Hrma Jan 2022

The Effects Of Mixing Multi-Component Hlw Glasses On Spinel Crystal Size, C. (Charmayne) E. Lonergan, J. Rice, C. Skidmore, M. J. Schweiger, P. Hrma

Materials Science and Engineering Faculty Research & Creative Works

The Hanford Waste Treatment and Immobilization Plant will vitrify radioactive waste into borosilicate glass. The high-level waste (HLW) glass formulations are constrained by processing and property requirements, including restrictions aimed at avoiding detrimental impacts of spinel crystallization in the melter. To understand the impact of glass chemistry on crystallization, two HLW glasses precipitating small (∼5 μm) spinel crystals were individually mixed and melted with a glass that precipitated large (∼45 μm) spinel crystals in ratios of 25, 50, and 75 wt.%. The size of spinel crystals in the mixed glasses varied from 5 to 20 μm. Small crystal size was …

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Microstructural And Optical Properties Of Mgal2o4 Spinel: Effects Of Mechanical Activation, Y2o3 And Graphene Additions, Nina Obradovic, William Fahrenholtz, Cole Corlett, Suzana Filipovic, Marko Nikolic, Bojan A. Marinkovic, Simone Failla, Diletta Sciti, Daniele Di Rosa, Elisa Sani Dec 2021

Microstructural And Optical Properties Of Mgal2o4 Spinel: Effects Of Mechanical Activation, Y2o3 And Graphene Additions, Nina Obradovic, William Fahrenholtz, Cole Corlett, Suzana Filipovic, Marko Nikolic, Bojan A. Marinkovic, Simone Failla, Diletta Sciti, Daniele Di Rosa, Elisa Sani

Materials Science and Engineering Faculty Research & Creative Works

Magnesium Aluminate and Other Alumina-Based Spinels Attract Attention Due to their High Hardness, High Mechanical Strength, and Low Dielectric Constant. MgAl2O4 Was Produced by a Solid-State Reaction between MgO and Α-Al2O3 Powders. Mechanical Activation for 30 Min in a Planetary Ball Mill Was Used to Increase the Reactivity of Powders. Yttrium Oxide and Graphene Were Added to Prevent Abnormal Grain Growth during Sintering. Samples Were Sintered by Hot Pressing under Vacuum at 1450◦C. Phase Composition and Microstructure of Sintered Specimens Were Characterized by X-Ray Powder Diffraction and Scanning Electron Microscopy. Rietveld Analysis Revealed 100% …

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Dechlorination Apparatus For Treating Chloride Salt Wastes: System Evaluation And Scale-Up, Brian J. Riley, Saehwa Chong, Charmayne E. Lonergan Nov 2021

Dechlorination Apparatus For Treating Chloride Salt Wastes: System Evaluation And Scale-Up, Brian J. Riley, Saehwa Chong, Charmayne E. Lonergan

Materials Science and Engineering Faculty Research & Creative Works

This paper describes an apparatus used to remove chlorine from chloride salt-based nuclear wastes from electrochemical reprocessing and/or chloride-based molten salt reactors (MSRs) through dechlorination by reacting the salts with ammonium dihydrogen phosphate (NH4H2PO4 or ADP) at temperatures up to 600 °C to produce NH4Cl as a byproduct. The benefits of removing the Cl from these salts include 37Cl recovery from Cl-based MSR salts, formation of UCl3 from the NH4Cl, as well as removal of Cl from the salts and conversion of the salt cations to oxides to allow …

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Impact Behavior Of Laminated Composites Built With Fique Fibers And Epoxy Resin: A Mechanical Analysis Using Impact And Flexural Behavior, Julian Rua, Mario F. Buchely, Sergio Neves Monteiro, Gloria I. Echeverri, Henry A. Colorado Sep 2021

Impact Behavior Of Laminated Composites Built With Fique Fibers And Epoxy Resin: A Mechanical Analysis Using Impact And Flexural Behavior, Julian Rua, Mario F. Buchely, Sergio Neves Monteiro, Gloria I. Echeverri, Henry A. Colorado

Materials Science and Engineering Faculty Research & Creative Works

This research analyzes the behavior of natural fiber reinforced laminated polymer composites (NFRPC) under mechanical solicitations. Samples were fabricated with epoxy resin matrix reinforced with a multilayer natural fique fiber in a bi-directional commercial fabric configuration. Different reinforcement contents without additives were prepared taking in the account the simplicity in processing, fabrication cost, and applications in which this material might be used with high performance standards. Charpy notched impact and 3-point bending test were carried out to evaluate the mechanical behavior and the work of fracture, which was improved significatively with the fibers, showing an increase from 5 to 30 …

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A Review On Alpha Case Formation And Modeling Of Mass Transfer During Investment Casting Of Titanium Alloys, R. Sharon Uwanyuze, Janos E. Kanyo, Sarah F. Myrick, Stefan Schafföner Jun 2021

A Review On Alpha Case Formation And Modeling Of Mass Transfer During Investment Casting Of Titanium Alloys, R. Sharon Uwanyuze, Janos E. Kanyo, Sarah F. Myrick, Stefan Schafföner

Materials Science and Engineering Faculty Research & Creative Works

Titanium alloys have excellent corrosion resistance, high temperature strength, low density, and biocompatibility. Therefore, they are increasingly used for aerospace, biomedical, and chemical applications. Investment casting is a well-established process for manufacturing near-net-shape intricate parts for such applications. However, mass transfer arising from metal-mold reactions is still a major problem that drastically impairs the surface and properties of the castings. Although there have been astounding developments over the past 20 years, they remain scattered in various research papers and conference proceedings. This review summarizes the current status of the field, gaps in the scientific understanding, and the research needs for …

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Removal Of Sb Impurities In Copper Electrolyte And Evaluation Of As And Fe Species In An Electrorefining Plant, Ana I. González De Las Torres, Michael S. Moats, Guillermo Ríos, Ana Rodríguez Almansa, Daniel Sánchez-Rodas Jun 2021

Removal Of Sb Impurities In Copper Electrolyte And Evaluation Of As And Fe Species In An Electrorefining Plant, Ana I. González De Las Torres, Michael S. Moats, Guillermo Ríos, Ana Rodríguez Almansa, Daniel Sánchez-Rodas

Materials Science and Engineering Faculty Research & Creative Works

Antimony and arsenic concentrations and their oxidation states (Sb(III), Sb(V), As(III) and As(V)) in copper electrorefining electrolyte can affect copper cathode quality through the formation of floating slimes. A laboratory-scale pilot plant was operated to remove Sb from commercial electrolyte. The pilot plant consisted of a pre-treatment process with copper shavings followed by ion exchange. The results indicated that Sb(III) was removed from copper electrolyte completely, while Sb(V) was partially eliminated. The concentrations of As(III) and As(V) were not affected, and the poisoning of the ion exchange resin by Fe(III) was avoided by pre-reduction to Fe(II) by copper shavings. The …

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Fabricating Tinicu Ternary Shape Memory Alloy By Directed Energy Deposition Via Elemental Metal Powders, Yitao Chen, Xinchang Zhang, Mohammad Masud Parvez, Joseph William Newkirk, Frank W. Liou Jun 2021

Fabricating Tinicu Ternary Shape Memory Alloy By Directed Energy Deposition Via Elemental Metal Powders, Yitao Chen, Xinchang Zhang, Mohammad Masud Parvez, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In this paper, a TiNiCu shape memory alloy single-wall structure was fabricated by the directed energy deposition technique with a mixture of elemental Ti, Ni, and Cu powders following the atomic percentage of Ti50Ni45Cu5 to fully utilize the material flexibility of the additive manufacturing process to develop ternary shape memory alloys. The chemical composition, phase, and material properties at multiple locations along the build direction were studied, using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Vickers hardness test-ing, tensile testing, and differential scanning calorimetry. The location-dependent compositions of martensitic TiNi and austenitic TiNi phases, mechanical properties, and functional properties …

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Mechanical Properties, Translucency, And Low Temperature Degradation (Ltd) Of Yttria (3–6 Mol%) Stabilized Zirconia, R. Sharon Uwanyuze, Sulekha Ramesh, Mark K. King, Nathaniel Lawson, Manoj K. Mahapatra Jun 2021

Mechanical Properties, Translucency, And Low Temperature Degradation (Ltd) Of Yttria (3–6 Mol%) Stabilized Zirconia, R. Sharon Uwanyuze, Sulekha Ramesh, Mark K. King, Nathaniel Lawson, Manoj K. Mahapatra

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties (hardness and biaxial flexural strength), optical properties (translucency and gloss), and low temperature degradation (LTD) of 3–6 mol% yttria stabilized zirconia have been investigated. The specimens were prepared by conventional solid-state sintering at 1400 °C. The mechanical and optical properties were evaluated for sintered and polished specimens. X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used, respectively, for structural and microstructural investigation. LTD was determined by XRD analysis of the samples aged in a hydrothermal autoclave at 134 °C for 5–108 h. The mechanical and optical properties are found to be microstructure sensitive. The LTD, due …

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Cyclic Regeneration Of Nanostructured Composites For Catalytic Applications, Fatih Dogan May 2021

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 and at a temperature between …

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Steam Oxidation Of Ytterbium Disilicate Environmental Barrier Coatings With And Without A Silicon Bond Coat, Ken A. Kane, Eugenio Garcia, Sharon Uwanyuze, Michael Lance, Kinga A. Unocic, Sanjay Sampath, Bruce A. Pint May 2021

Steam Oxidation Of Ytterbium Disilicate Environmental Barrier Coatings With And Without A Silicon Bond Coat, Ken A. Kane, Eugenio Garcia, Sharon Uwanyuze, Michael Lance, Kinga A. Unocic, Sanjay Sampath, Bruce A. Pint

Materials Science and Engineering Faculty Research & Creative Works

The current generation of multilayer Si/Yb2Si2O7 environmental barrier coatings (EBCs) are temperature limited by the melting point of Si, 1414°C. To investigate higher temperature EBCs, the cyclic steam oxidation of EBCs comprised of a single layer of ytterbium disilicate (YbDS) was compared to multilayered Si/YbDS EBCs, both deposited on SiC substrates using atmospheric plasma spray. After 500 1-h cycles at 1300°C in 90 vol%H2O-10 vol%air with a gas velocity of 1.5 cm/s, both multilayer Si/YbDS and single layer YbDS grew thinner silica scales than bare SiC, with the single layer YbDS forming the …

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Absorption Of Nitrogen During Pulsed Wave L-Pbf Of 17-4 Ph Steel, Ben Brown, Joseph William Newkirk, Frank W. Liou Feb 2021

Absorption Of Nitrogen During Pulsed Wave L-Pbf Of 17-4 Ph Steel, Ben Brown, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In the fabrication of 17-4 PH by laser powder bed fusion (L-PBF) the well-documented occurrence of large amounts of retained austenite can be attributed to an elevated concentration of nitrogen present in the material. While the effects of continuous wave (CW) laser processing on in-situ nitrogen absorption characteristics have been evaluated, power modulated pulsed wave (PW) laser processing effects have not. In this study the effects of PW L-PBF processing of 17-4 PH on nitrogen absorption, phase composition, and mechanical performance are explored using commercially available PW L-PBF equipment and compared to samples produced by CW L-PBF. PW L-PBF samples …

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Thermodynamic Prediction And Experimental Verification Of Multiphase Composition Of Scale Formed On Reheated Alloy Steels, Richard Osei, Semen Naumovich Lekakh, Ronald O'Malley Feb 2021

Thermodynamic Prediction And Experimental Verification Of Multiphase Composition Of Scale Formed On Reheated Alloy Steels, Richard Osei, Semen Naumovich Lekakh, Ronald O'Malley

Materials Science and Engineering Faculty Research & Creative Works

The structure, phase, and composition of scale formed on a continuously cast steel slab during reheating depend on intrinsic factors (steel chemistry, microstructure, and as-cast surface condition) and extrinsic parameters (temperature, time, composition, and velocity of combustion gas atmosphere). The scale that forms on a slab normally has several layers with differing compositions and phases and knowledge of this scale structure is important in subsequent descaling and hot rolling processing steps. Formation of multiphase scale structures on steel during high temperature oxidation in reheat furnace proceeds according to a local thermodynamic equilibrium, while thickness of layers depends on kinetic conditions …

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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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Optimization And Characterization Of Novel Injection Molding Process For Metal Matrix Syntactic Foams, Myranda Spratt, Joseph William Newkirk Dec 2020

Optimization And Characterization Of Novel Injection Molding Process For Metal Matrix Syntactic Foams, Myranda Spratt, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

Metal matrix syntactic foams are particulate composites comprised of hollow or porous particles embedded in a metal matrix. These composites are difficult to manufacture due primarily to the lightweight, relatively fragile filler material. In this work, an injection molding process was developed for metal matrix syntactic foams. First, an aqueous binder was optimized for low-pressure injection molding. A mixture model was used to optimize the composition of the binder to achieve the highest relative density. The model predicted the maximum relative density was at a binder composition (in vol.%) of 7% agar, 4% glycerin, and 89% water. Second, this binder …

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An Overview Of Ceramic Molds For Investment Casting Of Nickel Superalloys, Janos E. Kanyo, Stefan Schafföner, R. Sharon Uwanyuze, Kaitlynn S. Leary Dec 2020

An Overview Of Ceramic Molds For Investment Casting Of Nickel Superalloys, Janos E. Kanyo, Stefan Schafföner, R. Sharon Uwanyuze, Kaitlynn S. Leary

Materials Science and Engineering Faculty Research & Creative Works

Accelerating advancements in technological systems have demonstrated a need for alloys with drastically improved thermomechanical and chemical properties, called superalloys. Ceramic molds are typically used in near-net shape investment casting processes of superalloy components due to their chemical inertness and high-temperature capabilities. Ceramic molds, however, often suffer from shortcomings in vital properties including flexural strength, thermal shock resistance, permeability, dimensional stability, corrosion resistance, and leachability, which have restricted their ability to adequately process modern alloy castings. This study analyses these limitations and illustrates how to address them, particularly regarding ceramic mold and slurry design, processing of shells and cores, material …

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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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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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Framing Energy And Minerals For Future Pathways, Michelle Michot Foss, Michael S. Moats, Kwame Awuah-Offei Oct 2020

Framing Energy And Minerals For Future Pathways, Michelle Michot Foss, Michael S. Moats, Kwame Awuah-Offei

Materials Science and Engineering Faculty Research & Creative Works

We present a challenge for Group of Twenty (G20) discussions that entails (1) greater awareness of the role of non-fuel minerals in the global economy overall, but specifically in the energy sector; and (2) the introduction and acceleration of alternative energy sources and technologies. We focus on chemical battery energy storage, given its prominence in all views and outlooks of energy futures, especially for mobility. We present recommendations for G20 discussions and actions on battery materials, and the crucial underlying supply chains for mineral commodities.

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Microstructural Influence On Mechanical Properties Of A Lightweight Ultrahigh Strength Fe-18mn-10al-0.9c-5ni (Wt%) Steel, Michael Piston, Laura Bartlett, Krista R. Limmer, Daniel M. Field Oct 2020

Microstructural Influence On Mechanical Properties Of A Lightweight Ultrahigh Strength Fe-18mn-10al-0.9c-5ni (Wt%) Steel, Michael Piston, Laura Bartlett, Krista R. Limmer, Daniel M. Field

Materials Science and Engineering Faculty Research & Creative Works

This study evaluates the role of thermomechanical processing and heat treatment on the microstructure and mechanical properties of a hot rolled, annealed, and aged Fe-18Mn-10Al-0.9C-5Ni (wt%) steel. The steel exhibited rapid age hardening kinetics when aged in the temperature range of 500-600 ⁰C for up to 50 h, which has been shown in other work to be the result of B2 ordering in the ferrite and K-carbide precipitation within the austenite matrix. The ultimate tensile strength increased from 1120 MPa in the annealed condition to 1230 MPa after 2 h of aging at 570 ⁰C. Charpy V-notch toughness was evaluated …

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The Influence Of Ti, Nb And V On The Hot Ductility Of As-Cast Microalloyed Steels, Madhuri Varadarajan, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh Sep 2020

The Influence Of Ti, Nb And V On The Hot Ductility Of As-Cast Microalloyed Steels, Madhuri Varadarajan, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh

Materials Science and Engineering Faculty Research & Creative Works

Microalloying with Ti, Nb and V, both individually and in combination, is a common method for producing steels with high strength and toughness. However, interaction with other elements and impurities can lead to cracking during continuous casting and rolling. The hot ductility of commercially cast V, Nb and Nb-V-Ti steels has been investigated using two experimental methods: tensile testing utilizing a servo-hydraulic load frame with a resistance furnace and thermomechanical testing using rapid joule heating. The temperature-dependent ductility of these steels is compared for both test methods. Factors that influence the ductility of these steels are discussed.

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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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New Experimental Apparatus To Investigate Hot Tearing Behavior In Steel, Yanru Lu, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh, Mario F. Buchely Sep 2020

New Experimental Apparatus To Investigate Hot Tearing Behavior In Steel, Yanru Lu, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh, Mario F. Buchely

Materials Science and Engineering Faculty Research & Creative Works

Hot tearing is a complex thermomechanical phenomenon occurring in the semi-solid region. Strain in this region can induce cracking and localized alloying element segregation. An apparatus for investigating hot tearing was developed utilizing a servo-motor controlled cylinder to apply a pre-determined amount of strain to the solidifying shell. A special mold was developed using filling and solidification modeling to ensure that dendrite growth was perpendicular to applied strain. A computer-automated system was utilized to control the strain and strain rate and measure the force and displacement. Solidification experiments utilizing AISI 1020 steel validated the apparatus capabilities and optimized testing parameters.

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Scale Formation On 430 Stainless Steel In A Simulated Slab Combustion Reheat Furnace Atmosphere, Richard Osei, Semen Naumovich Lekakh, Ronald J. O'Malley Sep 2020

Scale Formation On 430 Stainless Steel In A Simulated Slab Combustion Reheat Furnace Atmosphere, Richard Osei, Semen Naumovich Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Scale formed during slab reheating can be difficult to remove by high-pressure descaling, having a negative impact hot roll surface quality. A large-capacity thermogravimetric apparatus that replicates the combustion atmosphere and temperature in a slab reheat furnace was used to investigate scale formation on 430 stainless steel. Effects of reheating parameters (temperature, time and atmosphere) on oxidation kinetics were investigated. Oxidized samples were characterized by scanning electron microscopy, Raman spectroscopy and x-ray diffraction to document the microstructure and morphology of scale. Mechanisms for the formation of multi-layered oxide structures that complicate oxidation kinetics and scale removal are discussed.

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