Inclusion Engineering Through Deoxidation Practice Optimization For Enhanced Mechanical Properties Of Cast Cr-Ni-Mo Steel,
2026
Missouri University of Science and Technology
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,
2026
Missouri University of Science and Technology
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 …
Effect Of Wall Movement On Porosity Formation In Ductile Iron Castings Under Varying Processing Parameters,
2026
Georgia Southern University
Effect Of Wall Movement On Porosity Formation In Ductile Iron Castings Under Varying Processing Parameters, Shamsul Alam
College of Graduate Studies: Theses & Dissertations
Shrinkage porosity is a major defect that significantly impairs the mechanical properties and overall performance of ductile iron castings. Although graphite formation during solidification induces volumetric expansion, this expansion alone is insufficient to fully compensate for the shrinkage occurring throughout solidification. During the solidification and cooling of ductile iron, multiple phase transformations occur, resulting in dynamic volume changes that exert pressure on mold walls and internal cavities. These pressures can deform mold walls and casting surfaces, leading to defects such as swell and porosity, while also influencing shrinkage formation. This study aims to analyze the mechanisms of porosity formation and …
Effects Of Composition, Nodularity, Pouring Temperature, Inoculation, And Mold Strength On Wall-Movement In Sgi Castings During Solidification And Cooling,
2026
Georgia Southern University
Effects Of Composition, Nodularity, Pouring Temperature, Inoculation, And Mold Strength On Wall-Movement In Sgi Castings During Solidification And Cooling, Noah Brack
College of Graduate Studies: Theses & Dissertations
The iron-carbon casting alloy known as spheroidal graphite iron (SGI), nodular graphite iron, or ductile iron (DI) experiences complex volume changes during its solidification and cooling as graphite nodules and austenite form. These volume changes result in forces on the mold cavity walls and can deform the mold walls in cases when mold walls lack the strength to resist the deformation. This wall movement can cause the formation of casting defects such as swell, warped part geometry, and shrinkage porosity. Though this phenomenon has been studied in the past, it remains difficult to predict casting wall movement with existing data. …
Effect Of Elemental Additions On The Microstructure, Macrostructure, And Mechanical Properties Of Gray Iron,
2026
Georgia Southern University
Effect Of Elemental Additions On The Microstructure, Macrostructure, And Mechanical Properties Of Gray Iron, August E. Rautmann
College of Graduate Studies: Theses & Dissertations
Gray iron is composed primarily of an iron matrix and flake graphite, with the higher percentage of volume taken up by the iron matrix. The iron matrix is the transformation product of austenite, and this prior austenite structure is understood to affect the final grain structure. Grain structure affects the properties of a metal, with a finer structure recognized as beneficial for most properties. Thus, the refinement of austenite structure has potential in improving the material properties of gray iron. This study aims to advance the limited knowledge about the control of austenite grain size via elemental additions. Building off …
Comparative Evaluation Of Gating Systems In Femnal Castings,
2026
Missouri University of Science and Technology
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 …
Multiphysics Modeling Of Melt Pool Dynamics And Powder Bed Stability In Lpbf Of Inconel 718 For A Circular Cavity,
2026
Missouri University of Science and Technology
Multiphysics Modeling Of Melt Pool Dynamics And Powder Bed Stability In Lpbf Of Inconel 718 For A Circular Cavity, Nayan Pundhir, Oluwapelumi O. Adejumo, Kumbla Chandrashekhara, Joseph W. Newkirk, Heath Misak, Cesar Ortiz Rios
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Laser powder bed fusion (LPBF) is a metal additive manufacturing process in which a concentrated laser beam selectively melts successive powder layers to fabricate components. Final part quality is highly sensitive to process parameters such as hatch spacing, powder bed density, laser power, and scanning speed. In this study, a computational fluid dynamics model employing discrete element method has been developed in FLOW-3D to simulate LPBF of Inconel 718. The modeled powder bed incorporates particle size distribution data obtained from scanning electron microscopy and is evaluated for single-layer, single-track deposition over a circular cavity. The model captured melt pool dynamics …
Electron Beam Irradiation Effects On Bulk Metals: A Comparative Study Of Polycrystalline Versus Single-Crystalline Structures,
2026
Old Dominion University
Electron Beam Irradiation Effects On Bulk Metals: A Comparative Study Of Polycrystalline Versus Single-Crystalline Structures, A. A. Elmustafa, N. A. Sultana, A. H. Al-Allaq, M. Ojha, Y. S. Mohammed, J. Vennekate, H. Baumgart
Mechanical & Aerospace Engineering Faculty Publications
This study investigates the effects of electron beam (e-beam) irradiation on the mechanical and structural properties of eight bulk metallic samples, comprising both polycrystalline (PC) and single-crystalline (SC) forms of Ni, Cr, V, and Ti. These metals were evaluated as potential candidates for beam exit windows in high-power (MW-class) particle accelerators. The primary objective is to identify metals capable of withstanding the conditions of high-power/MW-class e-beam accelerators and serve effectively as exit windows. Selection criteria were based on each metal’s intrinsic properties, power dissipation capability, and irradiation-induced changes in mechanical behavior, including hardness, elastic modulus, and defect density. Comprehensive characterization …
Multidentate Surfactant-Dependent Synthesis Of Giant Iridium Superstructures,
2026
Old Dominion University
Multidentate Surfactant-Dependent Synthesis Of Giant Iridium Superstructures, Ramjee Balasubramanian, Maeren E. Hill
Chemistry & Biochemistry Faculty Publications
Giant superstructures of iridium, comprised of smaller spherical and slightly larger anisotropic nanoparticles, were synthesized by reducing iridium chloride in the presence of resorcinarene, a class of tetrameric macrocyclic polyphenols, with sodium borohydride in ethanol in 30 min under mild conditions. These superstructures were characterized by a range of techniques including TEM, HRTEM, EDS and other spectroscopic methods. The impact of the macrocyclic surfactant, its features and reaction conditions in dictating the formation of giant iridium superstructures was evaluated. The packing density of nanoparticles in these giant iridium superstructures could be altered qualitatively by varying the duration of the reaction, …
Feasibility Of Upcycling Spent Lithium-Ion Battery To Carbon Dioxide Capture Adsorbent,
2026
Bucknell University
Feasibility Of Upcycling Spent Lithium-Ion Battery To Carbon Dioxide Capture Adsorbent, Chimezie Frank Onwudinjo
Master’s Theses
This study investigates the feasibility of repurposing spent lithium-ion battery (SLIB) to lithium orthosilicate (Li4SiO4), a high temperature carbon dioxide sorbent. Two synthesis pathways including conventional acid-leaching method (Scenario 1) and a pyrolysis-based route (Scenario 2) were explored. Additionally, techno-economic analysis (TEA) and lifecycle assessment (LCA) of the two processes were also performed. Different analytical characterization techniques were performed to understand the material properties of Li4SiO4 including surface area, crystallinity, morphology and thermal stability. CO2 capture performance of the synthesized Li4SiO4 was tested in a thermogravimetric analyzer (TGA) using …
A Combined Stochastic And Physical Framework For Alloys And Metal Casting Processes Modeling,
2026
Missouri University of Science and Technology
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,
2026
Missouri University of Science and Technology
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,
2026
Missouri University of Science and Technology
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,
2026
Missouri University of Science and Technology
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 …
Breaking The Vapor Barrier And Scale: Revolutionizing Steel Quenching With Ultrasound Technology,
2026
The University of Akron
Breaking The Vapor Barrier And Scale: Revolutionizing Steel Quenching With Ultrasound Technology, Anthony O. Santos
Williams Honors College, Honors Research Projects
The quenching process is a fundamental heat treatment used to enhance material properties by heating steel to its austenitizing temperature and rapidly cooling it to form high-strength martensite. However, this process is often hindered by two surface barriers: the Leidenfrost effect (vapor blanket) and oxide scale. These cooling limitations restrict the use of steel in high-performance aerospace applications due to inconsistent material properties and unpredictable engineering properties. This research investigates the use of fully submersible, 50-watt 40 kHz ultrasound technology to improve cooling rates in a Jominy test [4]. Through numerical simulations and experimental validation, the study demonstrates that acoustic …
Optimization Of Post-Processing Methods For Additively Manufactured Metals,
2026
The University of Akron
Optimization Of Post-Processing Methods For Additively Manufactured Metals, Julia R. Carano
Williams Honors College, Honors Research Projects
Ultrasonic Nanocrystal Surface Modification (UNSM) is a process used to change the surface hardness of flat-faced materials. It is a machining process using a high-powered laser and a blunt-tipped tool at high speeds which aims to improve the uniformity of the surface on most metals. By heating and pressing the surface of the workpiece, the grains of the material become less rounded and more cohesive on a microscopic level. This, ideally, results in a workpiece with improved material properties. The changes were previously observed through hardness testing.
Fused Filament Fabrication Additive Manufacturing Of 17-4 Ph Stainless Steel: Process–Structure–Property Relationships In Magnetic Materials,
2026
Virginia Commonwealth University
Fused Filament Fabrication Additive Manufacturing Of 17-4 Ph Stainless Steel: Process–Structure–Property Relationships In Magnetic Materials, Maanav Patel
Theses and Dissertations
Additive manufacturing (AM) enables the fabrication of complex metallic components through layer-by-layer processing directly from digital models. Among AM techniques, material extrusion–based processes such as fused filament fabrication (FFF) provide an accessible method for producing metal parts using filament feedstocks composed of metal powders and polymer binders. When applied to precipitation-hardening stainless steels such as 17-4 PH, the processing route and heat treatments can influence the resulting microstructure and functional properties. This work investigates the magnetic behavior of 17-4 PH stainless steel fabricated using FFF and evaluates how heat treatment conditions influence measured magnetic properties. Samples were produced and analyzed …
Development Of Stronger, More Extrudable 6xxx Series Alloys For Automotive Applications,
2026
Michigan Technological University
Development Of Stronger, More Extrudable 6xxx Series Alloys For Automotive Applications, Eli A. Harma
Dissertations, Master's Theses and Master's Reports
6xxx alloys are widely used in automotive extrusion structures for their high specific strength and formability. Advanced designs require greater formability and strength, creating an opportunity for high-strength, formable alloys. The 6xxx series forms β”-Mg5Si6 precipitates during age hardening and develops a fibrous microstructure during extrusion, both strengthening the alloy. Increasing Mg and Si to form more β” decreases formability. Thus, modifying texture can increase strength without reducing formability. Current alloys like 6005A add Mn and Cr to form dispersoids that inhibit recrystallization and promote strengthening textures; however, high Mn and Cr concentrations reduce formability. Replacing Mn …
Methodology Development For Evaluating Relative Heat Checking Resistance Of Open-Die Forge Tooling,
2026
Michigan Technological University
Methodology Development For Evaluating Relative Heat Checking Resistance Of Open-Die Forge Tooling, Jack F. Schaller
Dissertations, Master's Theses and Master's Reports
Heat checking, characterized by biaxial networks of surface cracks induced by thermomechanical cycling, can cause premature failure of open-die forge tooling. To facilitate the evaluation of heat checking resistance of die steels, a simulation‑informed out-of-phase thermomechanical fatigue (OP-TMF) testing methodology was developed using 4330V steel as a baseline material. Temperature‑dependent material properties and flow stress data were collected and compiled into a material data file for use with finite element analysis software. Forging and cooling scenarios were simulated across a range of die preheat temperatures. Temperature and in-plane strain histories extracted from the die surface provided a foundation for laboratory …
Ion-Imprinted Polymer-Based Sensors For Toxic Metal-Ion Detection In Water: Coordination Chemistry, Transduction Strategies, And Environmental Applications,
2026
Old Dominion University
Ion-Imprinted Polymer-Based Sensors For Toxic Metal-Ion Detection In Water: Coordination Chemistry, Transduction Strategies, And Environmental Applications, Ghita Yammouri, Gymama Slaughter
Center for Bioelectronics Publications
Toxic metal contamination in aquatic environments remains a persistent threat to human health and ecosystems. Yet, the high cost, infrastructure demands, and centralized nature of conventional analytical methods constrain routine monitoring. Ion-imprinted polymers (IIPs), a subclass of molecularly imprinted polymers, have emerged as promising synthetic recognition materials for metal-ion sensing because they generate coordination-defined binding sites with high selectivity, chemical stability, low cost, and reusability. This review summarizes recent advances in Ion-imprinted polymer (IIP)-based sensing technologies for toxic metal-ion detection in water from 2016 to 2026. It examines the fundamental recognition chemistry of IIPs, major synthesis strategies used to generate …
