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Materials Science and Engineering Faculty Research & Creative Works

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Full-Text Articles in Metallurgy

Magnetic Field-Induced Transformation In Polycrystalline Ni2mnal Heusler Type Magnetic Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely, Laura N. Bartlett Jul 2026

Magnetic Field-Induced Transformation In Polycrystalline Ni2mnal Heusler Type Magnetic Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely, Laura N. Bartlett

Materials Science and Engineering Faculty Research & Creative Works

The martensitic and magnetic transformations, as well as the mechanical properties, of Ni₂MnAl alloys in as-cast (AC) and heat-treated (HT) conditions were investigated. Magnetic-field-induced strain was evaluated via magnetostriction, with reversible strains of 0.14% and 0.2% achieved in the martensitic phase at 2 K for the AC and HT alloys, respectively. Transformation temperatures and Curie temperatures were determined under constant applied magnetic field, revealing that γ-phase inclusions in the AC microstructure suppress antiferromagnetic domain response, yielding a lower magnetization (∼8.4 emu g⁻¹) compared to the HT alloy (∼13.4 emu g⁻¹). Both alloys exhibited hysteretic behavior in the martensitic state and …


Eliminating Barriers For The Implementation Of Automation In The Mining Industry, Sefiu O. Adewuyi, Kray Luxbacher, Kanagy David, Miller Ben, Miller Hugh, Michael Moats, Savit Mark Jun 2026

Eliminating Barriers For The Implementation Of Automation In The Mining Industry, Sefiu O. Adewuyi, Kray Luxbacher, Kanagy David, Miller Ben, Miller Hugh, Michael Moats, Savit Mark

Materials Science and Engineering Faculty Research & Creative Works

The integration of new technologies into U.S. mining operations is necessary for achieving continuous improvement in worker health and safety, as well as improving operational efficiency, but many have questioned why uptake of autonomy in the U.S. mining industry has been slow compared to other nations. Despite extensive research on mining automation, there remains a critical gap in understanding and systematically identifying the barriers to its adoption within the U.S. mining industry and globally. To quantify these barriers, a workshop model of data collection was employed. A total of 708 invitations were extended to professionals to participate in nine different …


Wasting The Risk, Or Risking The Waste? Understanding The Trends Of Critical Raw Material Loss Into Waste Streams During Copper And Aluminium Processing, Ella Lausberg, Joël Brugger, Rahul Ram, John R. Owen, Deanna Kemp, Micheal S. Moats, Jonathan Hamisi, Vanessa N.L. Wong Mar 2026

Wasting The Risk, Or Risking The Waste? Understanding The Trends Of Critical Raw Material Loss Into Waste Streams During Copper And Aluminium Processing, Ella Lausberg, Joël Brugger, Rahul Ram, John R. Owen, Deanna Kemp, Micheal S. Moats, Jonathan Hamisi, Vanessa N.L. Wong

Materials Science and Engineering Faculty Research & Creative Works

Many critical raw materials (CRM) necessary in the transition to carbon-neutral energy reside in the waste streams of mining projects, as they are by-products and often not recovered alongside the primary metal. This work aims to document (i) the loss and potential recovery of by-product metals during the host commodity processing and (ii) the consequences of non-recovery, via a multi-scale risk–reward analysis. The information on the deportment of by-product metals through processing circuits is crucial for treating them as a resource, without which they risk near-permanent loss when treated as 'waste'. We review the deportment of tellurium and selenium as …


Inclusion Engineering Through Deoxidation Practice Optimization For Enhanced Mechanical Properties Of Cast Cr-Ni-Mo Steel, Kingsley T. Amatanweze, Viraj A. Athavale, Simon Lekakh, Ronald J. O'Malley, Laura N. Bartlett Feb 2026

Inclusion Engineering Through Deoxidation Practice Optimization For Enhanced Mechanical Properties Of Cast Cr-Ni-Mo Steel, Kingsley T. Amatanweze, Viraj A. Athavale, Simon Lekakh, Ronald J. O'Malley, Laura N. Bartlett

Materials Science and Engineering Faculty Research & Creative Works

Deoxidation is an integral part of steelmaking, as it determines steel castability, cleanliness, and porosity levels of the final product. Steel quality is critical to its performance and can be sabotaged by impurities such as non-metallic inclusions and porosity. This study investigates the effects of four distinct deoxidation practices, using Al, Al-Ca, Zr-Ca, and Mn-Si respectively, on tensile strength, tensile ductility and impact toughness of a Cr-Ni-Mo steel. These deoxidation reactions were modeled on a commercially available thermodynamic software and possible inclusion product phases were predicted. The casting samples were studied on a scanning electron microscope (SEM) utilizing energy dispersive …


Post-Calcium Treatment Evolution Of Alumina (Al2o3) Inclusions Morphology, Naziru I. Fuseini, Ronald J. O'Malley, Todd P. Sander, Jeffrey D. Smith, Haiming Wen, Laura N. Bartlett Feb 2026

Post-Calcium Treatment Evolution Of Alumina (Al2o3) Inclusions Morphology, Naziru I. Fuseini, Ronald J. O'Malley, Todd P. Sander, Jeffrey D. Smith, Haiming Wen, Laura N. Bartlett

Materials Science and Engineering Faculty Research & Creative Works

The post-calcium morphological evolution of Al2O3 inclusions formed under high-oxygen supersaturation (~1000 ppm) was investigated through time-resolved sampling and quenching of aluminum-killed, calcium-treated steel. SEM-EDS analysis revealed the formation of angular two-phase CaO·Al2O3–CaS inclusions within 1 minute, gradually transforming into spherical liquid 12CaO·7Al2O3 and CaO·Al2O3 with a thin CaS layer around it. The 3D morphology of the CaS phase of the complex CaO·Al2O3–CaS inclusions observed at 1 minute appeared as a cone-cap attached to the partially modified CaO·Al2O3. This …


Comparative Evaluation Of Gating Systems In Femnal Castings, K. Balasubramanian, Laura Bartlett, M. Xu Jan 2026

Comparative Evaluation Of Gating Systems In Femnal Castings, K. Balasubramanian, Laura Bartlett, M. Xu

Materials Science and Engineering Faculty Research & Creative Works

To understand the efficiency of gating systems, four systems, namely AFS styled pressurized system, AFS styled non-pressurized system, naturally pressurized system with a side riser and a naturally pressurized system with a top riser, were studied. The naturally pressurized systems were provided with overflows which collected the incoming metal swirl while the pressurized and non-pressurized systems had runner wells. Parameters like velocity of metal flow, air entrapment, microporosity and Niyama criterion were considered, and a design was developed with a common pouring basin using solidification software. Two molds were 3D printed using carbonitride sand, and steel of composition Fe-29Mn-8.2Al-0.91C-0.88Si-0.49Mo was …


A Combined Stochastic And Physical Framework For Alloys And Metal Casting Processes Modeling, Simon N. Lekakh, Oleg Neroslavsky Jan 2026

A Combined Stochastic And Physical Framework For Alloys And Metal Casting Processes Modeling, Simon N. Lekakh, Oleg Neroslavsky

Materials Science and Engineering Faculty Research & Creative Works

High temperature metal casting processes have dualistic nature and conceptually consist of two parts of distinct processes: the first type is deterministic, strictly obeying the physical law, while the second type is stochastic. Therefore, the metal casting processes are not precisely predictable, and deterministic considerations cannot provide exact outcomes. To solve this problem, the combined stochastic and deterministic framework was suggested. The local processes were described using deterministic models for several parameter arrangements, while the distribution of these arrangements on macro level was calculated using stochastic approaches. The approach was used for cast alloy design, investment casting process optimization, and …


Thermal Transformations And Mechanical Properties Of All-D-Metal Mn2fecu Heusler-Type Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely Jan 2026

Thermal Transformations And Mechanical Properties Of All-D-Metal Mn2fecu Heusler-Type Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely

Materials Science and Engineering Faculty Research & Creative Works

All-d-metal Heusler alloys are emerging functional materials in which magnetic ordering, lattice distortion, and mechanical behavior are strongly coupled through d–d electronic interactions. This study systematically investigates the structural, thermal, magnetic, and mechanical properties of Mn₂FeCu synthesized within a Heusler-type compositional framework. SEM/EDS revealed a dual-phase FCC-based microstructure consisting of Mn–Fe–rich and Mn–Cu–rich domains, while XRD confirmed FCC symmetry with compositional partitioning rather than full L2₁ ordering. Differential scanning calorimetry identified partial melting of the Cu-rich phase near ~ 900 °C. Dilatometry showed a thermoelastic FCC → FCT transformation at ~ 770–780 °C with a recoverable strain of ~ 0.067%. …


Design Of Novel Gating Systems For Steel Castings, K. Balasubramanian, Laura Bartlett, M. Xu Jan 2026

Design Of Novel Gating Systems For Steel Castings, K. Balasubramanian, Laura Bartlett, M. Xu

Materials Science and Engineering Faculty Research & Creative Works

Gating systems play an important role in determining the quality and mechanical properties of castings. To understand the efficiency of gating systems, four systems, namely pressurized system, non-pressurized system, naturally pressurized system with a side riser and a naturally pressurized system with a top riser, were studied. The naturally pressurized systems were provided with overflows which collected the incoming metal swirl. Parameters like velocity of metal flow, air entrapment, microporosity and Niyama criterion were considered, and a design was developed with a common pouring basin. 8630 alloy was poured into two molds using a teapot ladle. The inclusion analysis revealed …


The Effects Of Mold Flux Contamination On Oxide Scale Formation And Hydro-Descaling Efficiency During Steel Processing, Tochukwu Princewill Ojiako, Richard Osei, Mario Buchely, Haiming Wen, Simon Lekakh, Ronald O'Malley Jan 2026

The Effects Of Mold Flux Contamination On Oxide Scale Formation And Hydro-Descaling Efficiency During Steel Processing, Tochukwu Princewill Ojiako, Richard Osei, Mario Buchely, Haiming Wen, Simon Lekakh, Ronald O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Oxide scale formation during thin-slab continuous casting has a complex structure, which is influenced by mold flux contamination, that modifies interfacial reactions during solidification, subsequent reheating, and descaling. While individual aspects of the oxidation behavior of carbon steel have been previously examined, the synergetic effects of mold flux contamination during continuous casting and subsequent reheating on scale modification and the efficiency of hydraulic descaling remain inadequately studied. This study quantitatively examines the effect of flux composition on oxide scale evolution, adhesion, and hydraulic removal in low-carbon steel under simulated industrial conditions. Slab samples with as-cast, cleaned, and flux-coated surfaces were …


N-Radii Approach For Multi-Scale Characterization Of Graphite Shape In Cast Iron, Simon N. Lekakh, Laura Bartlett Jan 2026

N-Radii Approach For Multi-Scale Characterization Of Graphite Shape In Cast Iron, Simon N. Lekakh, Laura Bartlett

Materials Science and Engineering Faculty Research & Creative Works

Knowledge of multi-scale particle macro-shape and micro-surface topology is critical in many technical disciplines. Specifically, quality assessment of the shape of the graphite phase in cast irons is essential for day-to-day metal casting operations. Common methods for evaluating particle macro-shape have several drawbacks, often resulting in underestimation of sharp corners and surface texture. In this article, a method based on plotting n-radii from the center of mass to the perimeter and computing multi-scale topological characteristics is described and tested. Parametric tests, involving variations in the number of n-radii and image resolution, were performed to optimize the test parameters. The method …


Modeling Of Transformation Temperatures In Cast Martensitic Stainless Steels-Ca6nm: Effects Of Composition, Heating Rate, And Grain Size, Ugochukwu Agbedo, Mario Buchely, Laura Bartlett, Caelan Kennedy Jan 2026

Modeling Of Transformation Temperatures In Cast Martensitic Stainless Steels-Ca6nm: Effects Of Composition, Heating Rate, And Grain Size, Ugochukwu Agbedo, Mario Buchely, Laura Bartlett, Caelan Kennedy

Materials Science and Engineering Faculty Research & Creative Works

Accurate prediction of the critical transformation temperatures Ac1 and Ac3 is one of the essential factors in the heat treatment of CA6NM cast martensitic stainless steel. In this study, the influence of alloy composition, heating rate, and prior austenite grain size on the critical temperatures was quantified using dilatometric measurements and statistical modeling. Six heat treatment conditions produced prior austenite grain sizes ranging from ~75 to 247 µm. Experimental results showed that grain size variations produced only minor changes in Ac1 and Ac3, indicating a weak dependence of transformation temperatures on prior austenite grain size within the investigated range. In …


Multiphysics Simulation And Experimental Validation Of Phase Transformation And Hardness In Jominy End-Quenched Low-Alloy Steels, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. A. Athavale, A. Kumar Jan 2026

Multiphysics Simulation And Experimental Validation Of Phase Transformation And Hardness In Jominy End-Quenched Low-Alloy Steels, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. A. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

High-volume industrial continuous hot-rolled steel heat treatment processes involve sophisticated multi-phase modeling. The performance of a given process can be optimized by coupling phase transformation kinetics with the cooling conditions of the process. This study develops a multiphysics model to simulate an intensive quenching process for steel, which is inherently transient and highly dependent on numerous parameters. The simulated object was a Jominy end-quenched specimen geometry using two commercial steels, AISI 4130 and AISI 4140, with the goal of transferring a verified methodology to the heat treatment process for industrial heavy-section products (bars, slabs). The simulation employs thermal, mechanical, and …


Chemistry Of Inclusions By Size In Three Primary Copper Anodes, Charles Campbell, Michael Moats Oct 2025

Chemistry Of Inclusions By Size In Three Primary Copper Anodes, Charles Campbell, Michael Moats

Materials Science and Engineering Faculty Research & Creative Works

Three copper anodes from different commercial electro refineries were characterized to measure inclusion chemistry, size (diameter), and morphology. An automated scanning electron microscope (SEM) paired with energy-dispersive X-ray spectroscopy (EDS) was used to examine hundreds of inclusions near the mold and set sides of each anode. The investigation revealed that in the two anodes with less impurities (99.65% Cu and 99.75% Cu), many of the inclusions were Cu2O with an average diameter of 2 microns. The greater impurity anode (99.05% Cu, 4076 ppm Pb, 1939 ppm As, 635 ppm Bi) contained significant numbers of complex oxide inclusions, averaging 4.6 microns …


Selective Nickel Leaching And Preparation Of Battery-Grade Nickel Carbonate From Copper-Rich Industrial Intermediate, Janaka Jayamini Wijenayake, Michael S. Moats, Lloyd Masuzyo Mseteka, Lana Alagha Oct 2025

Selective Nickel Leaching And Preparation Of Battery-Grade Nickel Carbonate From Copper-Rich Industrial Intermediate, Janaka Jayamini Wijenayake, Michael S. Moats, Lloyd Masuzyo Mseteka, Lana Alagha

Materials Science and Engineering Faculty Research & Creative Works

The rising demand for electric vehicles (EVs) has driven a significant increase in nickel consumption, a critical element in EV battery production. An industrially viable hydrometallurgical process was developed for the selective recovery of nickel from a copper-rich industrial intermediate, containing approximately 70 wt.% Cu and 6 wt.% Ni, predominantly as sulfides alongside minor impurities. Approximately 90% of nickel was selectively extracted via single-stage atmospheric pressure leaching using HCl and H2O2 at 95 °C for 12 h, with the majority of copper retained in the leach residue, which can be utilized as a valuable feedstock for copper smelters. The selectivity …


Tensile Performance Sensitivity To Variations Of Standard 17-4 Ph Heat Treatments On Lpbf-Produced Material, Ben Brown, Cory Read, Joseph Newkirk, Frank Liou Oct 2025

Tensile Performance Sensitivity To Variations Of Standard 17-4 Ph Heat Treatments On Lpbf-Produced Material, Ben Brown, Cory Read, Joseph Newkirk, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

Standard heat treatments for metals of a particular composition are typically designed with the assumption of a conventional starting microstructure, such as that produced by casting or wrought processing. When applied to metals fabricated by Laser Powder Bed Fusion (LPBF) metal additive manufacturing (AM), these heat treatments can produce inconsistent performance due to the unique as-built microstructures. This study investigates how modifications to standard heat treatments for 17-4 PH steel influence the microstructure and mechanical properties of LPBF-fabricated material. Specimens were produced and subjected to varying solutionizing and homogenizing treatments followed by standard aging treatments. Microstructures were characterized using optical …


Impurity Behavior In Cast Copper Anodes: Implications For Electrorefining In A Circular Economy, Agustin Morales-Aragon, Daniel Sánchez-Rodas, Guillermo Ríos, Michael S. Moats Feb 2025

Impurity Behavior In Cast Copper Anodes: Implications For Electrorefining In A Circular Economy, Agustin Morales-Aragon, Daniel Sánchez-Rodas, Guillermo Ríos, Michael S. Moats

Materials Science and Engineering Faculty Research & Creative Works

The behavior of impurities in cast copper was investigated to simulate production with increased utilization of secondary sources within the framework of a circular economy. The incorporation of impurities, particularly Ni, Sn, and Sb, from recycled Cu may significantly impact the electrorefining process. In this study, commercial anodes were doped with Ni, Sn, and Sb concentrations of 2500–6500 g/t, 300–900 g/t, and 450–950 g/t, respectively. Anode concentrations of Pb and Bi were maintained at 1000 g/t and 350 g/t, respectively. As concentrations were examined at two levels, 860 or 1700 g/t, depending on the commercial anode used to create the …


Understanding Heterogeneous Nucleation In Iron Alloys From First Principles: A Review And Discussion, Semen Naumovich Lekakh Jan 2025

Understanding Heterogeneous Nucleation In Iron Alloys From First Principles: A Review And Discussion, Semen Naumovich Lekakh

Materials Science and Engineering Faculty Research & Creative Works

Heterogeneous nucleation during solidification plays a key role in structure formation of different types of iron-based alloys, including steels and cast irons. A review summarizes the novel theoretical methods which were used to understand the nature of heterogeneous nucleation in iron-based alloys. An ab initio simulation of atomic adsorption was used to predict the activity of heterogeneous nuclei, and the thermodynamic methods were applied to design conditions for desired precipitate formation in the iron melts. A high-resolution TEM study of individual nucleus and statistics of nuclei family, obtained from an automated SEM/EDX analysis, illustrates a possibility to design processes of …


High-Temperature Performance Of Alloyed Cast Irons And Cr/Ni Austenitic Steels—An Overview And Discussion, Simon N. Lekakh, Mei Li, Larry Godlewski Jan 2025

High-Temperature Performance Of Alloyed Cast Irons And Cr/Ni Austenitic Steels—An Overview And Discussion, Simon N. Lekakh, Mei Li, Larry Godlewski

Materials Science and Engineering Faculty Research & Creative Works

Fe-based cast alloys, including cast irons and steels, have been used in service at a wide range of mechanical and thermal load in oxidizing environment. Special alloying practices can be used to improve high temperature performance of Fe-based cast alloys in an oxidizing atmosphere. At elevated temperatures, alloying elements can produce a protective interface layer which prevents oxidant penetration into the metal matrix. However, a combination of thermo-mechanical loads along with surface oxidation can decrease the materials integrity by destroying the stable protected interface limiting the range of working parameters and lifetime performance of the material. This overview aims to …


The Effect Of Carbon Equivalent And Nodularity On Multi-Axial Casting Wall Movement During Spheroidal Graphite Iron Solidification And Cooling, Noah J. Brack, Mingzhi Xu, Jingjing Qing, Simon Lekakh Jan 2025

The Effect Of Carbon Equivalent And Nodularity On Multi-Axial Casting Wall Movement During Spheroidal Graphite Iron Solidification And Cooling, Noah J. Brack, Mingzhi Xu, Jingjing Qing, Simon Lekakh

Materials Science and Engineering Faculty Research & Creative Works

Spheroidal graphite iron, also known as ductile iron, is an iron–carbon casting alloy used in industry for its good castability, balanced mechanical properties, and low cost. Ductile iron consists of round graphite nodules in an iron matrix. During solidification and cooling, ductile iron castings experience dynamic volume changes due to the precipitation of graphite nodules and formation of austenite. These dynamic volume changes can distort external casting surfaces, causing swell and shrinkage porosity. A novel apparatus was custom-built to capture the casting wall movement in real time along three axes. This study found that casting expansion increased with carbon equivalent …


A Novel Technique For Improved Measurement Of Graphite And Inclusions In Ductile Iron Contaminated By Boron, Chase Schroeder, Colleen Lehrer, Simon Lekakh, Laura Bartlett Jan 2025

A Novel Technique For Improved Measurement Of Graphite And Inclusions In Ductile Iron Contaminated By Boron, Chase Schroeder, Colleen Lehrer, Simon Lekakh, Laura Bartlett

Materials Science and Engineering Faculty Research & Creative Works

The highly heterogeneous microstructure of ductile iron in casting includes graphite particles, non-metallic inclusions, microporosity, and other features, such as carbides distributed in the ferrite–pearlite matrix. Determination and comprehensive quantification of microstructural features are practically important however challenging. An advanced methodology based on an automated SEM/EDX analysis was developed and compared to the standard optical imaging method. In addition to backscattered electron contrast, sensitive to atomic number, a novel methodology added EDX data to identify and classify the multiple structural features at micron resolution thresholding. To quantify the shape of individual phases, the eight chord raster algorithms was used and …


Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field Jan 2025

Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field

Materials Science and Engineering Faculty Research & Creative Works

Nitrogen pickup during air induction melting can result in porosity and a loss of fracture toughness in ultrahigh-strength quenched and tempered steel castings. Nitrogen atoms are easily adsorbed into liquid steel upon exposure to the air, and argon shrouding alone has limited effectiveness. Previous studies have shown that proper charge sequencing and maintaining a high amount of dissolved oxygen in the melt prior to tapping and deoxidation can limit nitrogen pickup in the melt. In the current study, the effect of melt practice and charging procedure on nitrogen pickup was studied as a function of hold time in a series …


Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali Jan 2025

Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali

Materials Science and Engineering Faculty Research & Creative Works

Efficient oxide scale removal is critical for maintaining surface quality and process efficiency in steel manufacturing. This study optimizes water jet descaling by evaluating the performance of flat and rotary jet nozzles under varying process parameters. Using a combined approach of experimental analysis and computational fluid dynamics, it investigates the influence of pressure (138–275 bar), lead angle (0°, 15°, 25°), working distance (50–100 mm), and spray angle (15°–25°) on descaling efficiency. Findings indicate that flat jet nozzles achieve superior performance at short working distances due to concentrated impact forces, while rotary jet nozzles sustain efficiency over extended distances through dynamic …


Roadmap To 100 Gwdc: Scientific And Supply Chain Challenges For Cdte Photovoltaics, B. Edward Sartor, Samantha B. Reese, Lorelle M. Mansfield, Ryan Muzzio, Chun Sheng Jiang, Eric Colegrove, John S. Mangum, Camden L. Kasik, Daniel Z. Shaw, James R. Sites, Ramesh G. Dhere, Alex B. Goldstone, Michael S. Moats Jan 2025

Roadmap To 100 Gwdc: Scientific And Supply Chain Challenges For Cdte Photovoltaics, B. Edward Sartor, Samantha B. Reese, Lorelle M. Mansfield, Ryan Muzzio, Chun Sheng Jiang, Eric Colegrove, John S. Mangum, Camden L. Kasik, Daniel Z. Shaw, James R. Sites, Ramesh G. Dhere, Alex B. Goldstone, Michael S. Moats

Materials Science and Engineering Faculty Research & Creative Works

This roadmap highlights pathways to expand the CdTe module manufacturing capacity per year to 100 GWDC by 2030 by improving Te extraction from existing supply chains, minimizing Te usage in modules by leveraging thinner absorbers, and focusing research efforts in key areas to improve module efficiencies. Both scientific and supply chain innovations will be necessary to maintain the high compound annual growth rate of the CdTe photovoltaic (PV) industry and cement its role as a key technology for multi-TW-scale PV deployment.


Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck Jan 2025

Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck

Materials Science and Engineering Faculty Research & Creative Works

The effect of gating system design on the inclusion population and size distribution in an aluminum-killed low-alloy advanced high strength steel casting was studied. A mold with four different gating systems: pressurized and non-pressurized with side risers, naturally pressurized with a side riser, and naturally pressurized with a top riser, was designed using computational fluid dynamics and solidification software. The design allowed inclusion populations in castings produced with each gating system to be compared during the same pouring event. Samples taken from different positions just below the top surface of each casting were analyzed using an SEM/EDS system with automated …


Multiphysics Modeling And Experimental Validation Of High-Strength Steel In Laser Powder Bed Fusion Process, M. Rangapuram, S. Babalola, J. W. Newkirk, L. N. Bartlett, F. W. Liou, K. Chandrashekhara, Stephen R. Cluff Dec 2024

Multiphysics Modeling And Experimental Validation Of High-Strength Steel In Laser Powder Bed Fusion Process, M. Rangapuram, S. Babalola, J. W. Newkirk, L. N. Bartlett, F. W. Liou, K. Chandrashekhara, Stephen R. Cluff

Materials Science and Engineering Faculty Research & Creative Works

Laser powder bed fusion (LPBF) is a subset of the additive manufacturing process in which a laser beam selectively joins the metal powder into a desired part in a sequential layer process. Owing to its complex nature of rapid heating and cooling of the melt pool, there is a need to understand the melt pool behavior and its effects on the final manufactured part. a densely packed powder bed is highly desirable for fabricating a superior part using the LPBF process. in this work, discrete element model was used to generate powder beds with realistic powder properties and various factors …


A General Model For The Ductility Of Intermetallics Applied To Fe-Co Alloys, Wesley Everhart, Joseph Newkirk Dec 2024

A General Model For The Ductility Of Intermetallics Applied To Fe-Co Alloys, Wesley Everhart, Joseph Newkirk

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties, specifically ductility, of high performing soft magnets such as Fe-Co alloys are a limiting factor to their broader use in a number of systems. The understanding of the mechanical robustness in these materials is currently insufficient to be able to support the growing interest in applications such as magnetic shielding or electric motors. Fe-Co alloys provide the highest commercially available magnetic saturation and high magnetic permeability but have very poor ductility. The addition of vanadium to these alloys has allowed for significant commercialization and some ductility improvements, but the fundamental reasons for the observed improvements are not …


Atmosphere Effects In Laser Powder Bed Fusion: A Review, Ben Brown, Cody Lough, Davis Wilson, Joseph Newkirk, Frank Liou Nov 2024

Atmosphere Effects In Laser Powder Bed Fusion: A Review, Ben Brown, Cody Lough, Davis Wilson, Joseph Newkirk, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

The use of components fabricated by laser powder bed fusion (LPBF) requires the development of processing parameters that can produce high-quality material. Manipulating the most commonly identified critical build parameters (e.g., laser power, laser scan speed, and layer thickness) on LPBF equipment can generate acceptable parts for established materials and moderately intricate part geometries. The need to fabricate increasingly complex parts from unique materials drives the limited research into LPBF process control using underutilized parameters, such as atmosphere composition and pressure. As presented in this review, manipulating atmosphere composition and pressure in laser beam welding has been shown to expand …


Development Of Robust Steel Alloys For Laser-Directed Energy Deposition Via Analysis Of Mechanical Property Sensitivities †, Jonathan Kelley, Joseph W. Newkirk, Laura N. Bartlett, Sriram Praneeth Isanaka, Todd Sparks, Saeid Alipour, Frank Liou Oct 2024

Development Of Robust Steel Alloys For Laser-Directed Energy Deposition Via Analysis Of Mechanical Property Sensitivities †, Jonathan Kelley, Joseph W. Newkirk, Laura N. Bartlett, Sriram Praneeth Isanaka, Todd Sparks, Saeid Alipour, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

To ensure consistent performance of additively manufactured metal parts, it is advantageous to identify alloys that are robust to process variations. This paper investigates the effect of steel alloy composition on mechanical property robustness in laser-directed energy deposition (L-DED). In situ blending of ultra-high-strength low-alloy steel (UHSLA) and pure iron powders produced 10 compositions containing 10–100 wt.% UHSLA. Samples were deposited using a novel configuration that enabled rapid collection of hardness data. The Vickers hardness sensitivity of each alloy was evaluated with respect to laser power and interlayer delay time. Yield strength (YS) and ultimate tensile strength (UTS) sensitivities of …


Ijmc/Fef Student Research Competition: Understanding The Effect Of Boron On Graphite Nodularity And Distribution In Ductile Iron Castings, Chase Schroeder, Colleen Lehrer, Simon Lekakh, Laura Bartlett Jan 2024

Ijmc/Fef Student Research Competition: Understanding The Effect Of Boron On Graphite Nodularity And Distribution In Ductile Iron Castings, Chase Schroeder, Colleen Lehrer, Simon Lekakh, Laura Bartlett

Materials Science and Engineering Faculty Research & Creative Works

Ductile iron is renowned for its superior mechanical properties, higher strength, and ductility, combined with excellent castability and the economy of using a scrap melting process. The matrix structure as well as morphology and distribution of graphite nodules significantly influences mechanical properties of as-cast ductile iron. Boron contamination of the scrap supply has presented some difficulties in controlling the microstructure and mechanical properties of certain gray and ductile iron grades. In the current study, the effect of boron levels up to 95 ppm was determined on graphite nodularity and distribution in as-cast ductile iron castings as a function of section …