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Missouri University of Science and Technology

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Articles 271 - 300 of 2218

Full-Text Articles in Materials Science and Engineering

Transitioning To A Lower Global Warming Refrigerant, A Performance Study Of R-513a And Hfc-134a In Commercial Chillers, Hossein Abedsoltan, Mark B. Shiflett Jan 2024

Transitioning To A Lower Global Warming Refrigerant, A Performance Study Of R-513a And Hfc-134a In Commercial Chillers, Hossein Abedsoltan, Mark B. Shiflett

Chemical and Biochemical Engineering Faculty Research & Creative Works

The performance of R-513A and HFC-134a refrigerants is compared in two identical chillers operating at the University of Kansas. R-513A is a more environmentally friendly refrigerant due to its lower global warming potential that can be used as a retrofit replacement for HFC-134a in chillers. This study investigates the performance comparison of transitioning from HFC-134a to R-513A. The chillers have been in operation for two years, and cooling capacity, coefficient of performance, and other operating parameters are compared under similar cooling conditions. Cooling capacities ranged from 100 to 500 kW for both chillers. Overall, the energy consumption and coefficient of …

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Development And Testing Of High Strength Scalable High Entropy Alloys, Hans Jakob Pommerenke Jan 2024

Development And Testing Of High Strength Scalable High Entropy Alloys, Hans Jakob Pommerenke

Doctoral Dissertations

"High entropy alloys have shown promise through their ability to be tailored to specific scenarios. From highly corrosive environments to precipitation strengthened alloys to radiation environments high entropy alloys allow tailor made alloys for every solution. New compositions are developed and tested but little work focuses on the processing effect choosing rather than using processing as a steppingstone to achieve properties without investigating the processing effects. This work focuses on single phase face-centered cubic alloys strengthened by processing and precipitation strengthening. In conjunction with the development of these alloys, the ability to scale production will be investigated and characterized to …

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The Development Of Hard Materials And Fibrous Monolith Composites For Friction Stir Welding, Paul Michael Brune Jan 2024

The Development Of Hard Materials And Fibrous Monolith Composites For Friction Stir Welding, Paul Michael Brune

Doctoral Dissertations

"This research focuses on the development of hard materials and fibrous monolith composites for the purpose of adding to current friction stir welding tool technology. Well studied hard material systems, such as WC-Co, were incorporated and evaluated as cell materials for fibrous monolith composites with ductile cell boundaries of Co, W, and Mo. The indentation behavior of the WC-Co and WC-Co-cBN composites indicated possible crack deflection at the cell/cell boundary interface. Cylindrical pin friction stir welding tools were developed for each of the three fibrous monolith material systems. Welding was achieved on AA1100 aluminum, 260 brass, and AISI 1018 steel …

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A Lab-Scale Mold Simulator Employing An Optical-Fiber-Instrumented Mold To Characterize Initial Steel Shell Growth Phenomena, Muhammad A. Nazim, Rony K. Saha, Mario F. Buchely, Ronald J. O'Malley, Jie Huang, Arezoo Emdadi Jan 2024

A Lab-Scale Mold Simulator Employing An Optical-Fiber-Instrumented Mold To Characterize Initial Steel Shell Growth Phenomena, Muhammad A. Nazim, Rony K. Saha, Mario F. Buchely, Ronald J. O'Malley, Jie Huang, Arezoo Emdadi

PSMRC Faculty Research

A mold simulator was developed to replicate the mold oscillation and casting speed conditions of a continuous caster on the lab scale. A mold was designed incorporating fiber optics to capture internal temperature gradients and transient heat transfer phenomena during the initial solidification of steel. Casting parameters (casting speed, oscillation stroke and oscillation frequency) were investigated using the mold simulator. Solidified steel shells and mold thermal data were collected and characterized after initial solidification to investigate the impacts of mold oscillation on shell growth and mold heat transfer.

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Femtosecond Laser–Inscribed Fiber Bragg Grating Sensors: Enabling Distributed High- Temperature Measurements And Strain Monitoring In Steelmaking And Foundry Applications, Ogbole Collins Inalegwu, Yeshwanth Reddy Mekala, Rony Kumer Saha, Farhan Mumtaz, Dinesh Reddy Alla, Deva Prasaad Neelakandan, Jeffrey D. Smith, Ronald J. O'Malley, Rex Gerald, Jie Huang Jan 2024

Femtosecond Laser–Inscribed Fiber Bragg Grating Sensors: Enabling Distributed High- Temperature Measurements And Strain Monitoring In Steelmaking And Foundry Applications, Ogbole Collins Inalegwu, Yeshwanth Reddy Mekala, Rony Kumer Saha, Farhan Mumtaz, Dinesh Reddy Alla, Deva Prasaad Neelakandan, Jeffrey D. Smith, Ronald J. O'Malley, Rex Gerald, Jie Huang

PSMRC Faculty Research

This study demonstrates the use of fiber Bragg grating (FBG) sensors for distributed temperature and strain monitoring in steelmaking and foundry applications. Integrated into inexpensive optical fibers, FBGs offer accurate and real-time remote sensing, detecting shifts in wavelength due to temperature (up to 1,800 °C), strain, or structural wear and tear. Furthermore, the intrinsic features of FBG sensors: compact size, immunity to electromagnetic interference and corrosion, robustness to vibration, ease of integration into existing composite structures, and non-intrusive measurement capacity in harsh environments make them ideal for steelmaking. FBGs optimize production, ensure quality, and enhance safety within the steel industry.

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Enhanced Bottom Anode Monitoring In Dc Electric Arc Furnaces Using Fiber Optic Sensors, Yeshwanth Reddy Mekala, Rony Kumer Saha, Ogbole Collins Inalegwu, Muhammad Roman, Farhan Mumtaz, Rex Gerald, Jeffrey D. Smith, Jie Huang, Ronald J. O'Malley Jan 2024

Enhanced Bottom Anode Monitoring In Dc Electric Arc Furnaces Using Fiber Optic Sensors, Yeshwanth Reddy Mekala, Rony Kumer Saha, Ogbole Collins Inalegwu, Muhammad Roman, Farhan Mumtaz, Rex Gerald, Jeffrey D. Smith, Jie Huang, Ronald J. O'Malley

PSMRC Faculty Research

A pin style bottom anode employs conductive steel rods that serve as the pathway for the high electrical power through rammed refractory at the bottom of a DC Electric Arc Furnace (EAF). Anode wear during operation is important to monitor, as anode replacement is expensive and impacts EAF productivity. Liquid steel penetration into the un-sintered refractory layer can result from rapid electrical power ramp-up, dips in furnace temperature, or operating the anode for too long between EAF campaigns. In extreme cases, the liquid steel may penetrate the bottom of the furnace when anode wear progresses too close to the bottom …

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Fiber-Optic Raman Probe For On-Line Eaf Slag Analysis, Bohong Zhang, Hanok Tekle, Jeffrey D. Smith, Todd Sander, Ronald J. O'Malley, Jie Huang Jan 2024

Fiber-Optic Raman Probe For On-Line Eaf Slag Analysis, Bohong Zhang, Hanok Tekle, Jeffrey D. Smith, Todd Sander, Ronald J. O'Malley, Jie Huang

PSMRC Faculty Research

In Electric Arc Furnace (EAF) steelmaking, the push for improved efficiency requires accurate analysis of the chemical composition of its slag system to control slag foaming, provide refractory protection, and maintain high furnace iron yield. Therefore, the ability to obtain real-time slag chemistry data would provide a useful tool to improve the control and efficiency of the process. The work reported here aims to assess the structure and chemistry of EAF slags at high temperatures using a portable fiber-optic Raman probe. The ability to relate Raman spectra peaks to chemistry and structure is demonstrated in experimental result with EAF slags …

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The Melting Behavior Of Hydrogen Direct Reduced Iron In Molten Steel And Slag: An Integrated Computational And Experimental Study, Fabian Andres Calderon Hurtado, Joseph Govro, Arezoo Emdadi, Ronald J. O'Malley Jan 2024

The Melting Behavior Of Hydrogen Direct Reduced Iron In Molten Steel And Slag: An Integrated Computational And Experimental Study, Fabian Andres Calderon Hurtado, Joseph Govro, Arezoo Emdadi, Ronald J. O'Malley

PSMRC Faculty Research

Direct reduced iron (DRI) and hot briquetted iron (HBI) are essential feedstocks for tramp element control in the electric arc furnace (EAF). Due to greenhouse gas (GHG) concerns related to CO2 emissions, hydrogen as a substitute for natural gas and a reductant in DRI production is being widely explored to reduce GHG emissions in ironmaking. This study examines the melting behavior of hydrogen DRI (H-DRI) pellets in the EAF containing low-carbon (0.1 wt.%) molten steel and molten slag. A computational heat transfer model was developed to predict the melting behavior of H-DRI pellets. To validate the model, a set …

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Ai-Enabled Assessment Of Roadway Integrity: Forecasting Bitumen Deformation And Road Stability Throughout The Lifecycle Under Traffic Impact, Sabahudin Vrtagic, Milan Dordevic, Fatih Dogan, Muhammed Codur, Mario Hoxha, Edis Softic Dec 2023

Ai-Enabled Assessment Of Roadway Integrity: Forecasting Bitumen Deformation And Road Stability Throughout The Lifecycle Under Traffic Impact, Sabahudin Vrtagic, Milan Dordevic, Fatih Dogan, Muhammed Codur, Mario Hoxha, Edis Softic

Materials Science and Engineering Faculty Research & Creative Works

Asphalt-paved Road junctions frequently encounter deformation and degradation challenges due to heavy vehicular traffic and varying climatic conditions, such as temperature fluctuations and precipitation. This study employs a multifaceted approach, incorporating a Multilayer Perceptron (MLP) model, ancillary machine learning techniques, and optimization methodologies, to address these challenges effectively. The primary objectives are the prediction and analysis of pavement deformation, the optimization of maintenance strategies, and the evaluation of road effectiveness. Our findings underscore the substantial contribution of heavy vehicles to road erosion and the profound impact of vehicular retention and braking at intersections. A Multilayer Perceptron (MLP) model is utilized …

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Microstructure, Mechanical Properties And Oxidation Behavior Of Refractory Multi-Principal Element Alloys By Laser Remelting And Conventional Manufacturing, Visharad Jalan, Seth Crawford, Sung Heng Wu, Frank Liou, Haiming Wen Dec 2023

Microstructure, Mechanical Properties And Oxidation Behavior Of Refractory Multi-Principal Element Alloys By Laser Remelting And Conventional Manufacturing, Visharad Jalan, Seth Crawford, Sung Heng Wu, Frank Liou, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Refractory multi-principal element alloys (RMPEAs), HfNbTaTiZr, (HfNbTaTiZr)9Cr, and (HfNbTaTiZr)9Al, were manufactured using vacuum arc melting followed by laser remelting to mimic additive manufacturing. the microhardness of the as-cast HfNbTaTiZr, (HfNbTaTiZr)9Cr, and (HfNbTaTiZr)9Al samples after arc melting was measured as 6.20, 7.63, and 6.89 Gpa, respectively. after laser remelting and re-solidification, the hardness increased by ~ 30% for each composition; the hardest was (HfNbTaTiZr)9Cr measured at 9.60 GPa, while the softest was HfNbTaTiZr with a hardness of 8.42 GPa, which was still harder compared to all the other samples. the addition of Al and Cr led to enhanced oxidation resistance for …

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Modeling Hydration Kinetics Of Sustainable Cementitious Binders Using An Advanced Nucleation And Growth Approach, Taihao Han, Jie Huang, Gaurav Sant, Narayanan Neithalath, Ashutosh Goel, Aditya Kumar Nov 2023

Modeling Hydration Kinetics Of Sustainable Cementitious Binders Using An Advanced Nucleation And Growth Approach, Taihao Han, Jie Huang, Gaurav Sant, Narayanan Neithalath, Ashutosh Goel, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Supplementary cementitious materials (SCMs) are utilized to partially substitute Portland cement (PC) in binders, reducing carbon-footprint and maintaining excellent performance. Nonetheless, predicting the hydration kinetics of [PC + SCM] binders is challenging for current analytical models due to the extensive diversity of chemical compositions and molecular structures present in both SCMs and PC. This study develops an advanced phase boundary nucleation and growth (pBNG) model to yield a priori predictions of hydration kinetics—i.e., time-resolved exothermic heat release profiles—of [PC + SCM] binders. The advanced pBNG model integrates artificial intelligence as an add-on, enabling it to accurately simulate hydration kinetics for …

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Vacancy Ordering In Zirconium Carbide With Different Carbon Contents, Yue Zhou, Jeremy Lee Watts, Cheng Li, William Fahrenholtz, Gregory E. Hilmas Nov 2023

Vacancy Ordering In Zirconium Carbide With Different Carbon Contents, Yue Zhou, Jeremy Lee Watts, Cheng Li, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Zirconium carbide (ZrCx) ceramics with different carbon contents were prepared by reactive hot-pressing. The rock-salt structure of ZrCx was the only phase detected by x-ray diffraction of the hot pressed ceramics. The relative densities of ZrCx decreased as carbon content increased, in general. The actual carbon contents were measured by completely oxidizing the ZrCx ceramics to ZrO2. For most compositions, the actual carbon contents were higher than nominal batched compositions, presumably due to carbon uptake from the graphite furnace and hot press dies. Selected area electron diffraction and neutron powder diffraction revealed the presence of carbon vacancy ordering …

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Implementation Of Experimental Static Recrystallization Of High Strength Steel Into Computational Simulation Of Multi-Pass Slab Hot Rolling, S. K. Dasari, S. Ganguly, A. Abutunis, K. Chandrashekhara, M. F. Buchely, S. N. Lekakh, R. J. O'Malley, T. Natarajan Nov 2023

Implementation Of Experimental Static Recrystallization Of High Strength Steel Into Computational Simulation Of Multi-Pass Slab Hot Rolling, S. K. Dasari, S. Ganguly, A. Abutunis, K. Chandrashekhara, M. F. Buchely, S. N. Lekakh, R. J. O'Malley, T. Natarajan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microstructural changes and softening due to static recrystallization have a critical influence on thermo-mechanical behavior of high strength steels during industrial multi-pass hot rolling. Numerical simulation using finite element analysis (FEA) can be used to accurately predict the softening behavior during the hot rolling process. Therefore, the implementation of an experimentally defined static recrystallization model into FEA is necessary to get realistic simulation prediction. in this study, the extent of softening during static recrystallization in Si and Mn alloyed high strength steel was measured using double hit tests. a Gleeble™ thermo-mechanical simulator was used to perform the double hit tests …

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Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen Nov 2023

Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nanostructured steels are expected to have enhanced irradiation tolerance and improved strength. However, they suffer from poor microstructural stability at elevated temperatures. in this study, Fe–21Cr–5Al–0.026C (wt.%) Kanthal D (KD) alloy belonging to a class of (FeCrAl) alloys considered for accident-tolerant fuel cladding in light-water reactors is nanostructured using two severe plastic deformation techniques of equal-channel angular pressing (ECAP) and high-pressure torsion (HPT), and their thermal stability between 500–700 °C is studied and compared. ECAP KD is found to be thermally stable up to 500 °C, whereas HPT KD is unstable at 500 °C. Microstructural characterization reveals that ECAP KD …

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Boosting Snr Of Cascaded Fbgs In A Sapphire Fiber Through A Rapid Heat Treatment, Farhan Mumtaz, Hanok Tekle, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang Nov 2023

Boosting Snr Of Cascaded Fbgs In A Sapphire Fiber Through A Rapid Heat Treatment, Farhan Mumtaz, Hanok Tekle, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This Letter reports the performance of femtosecond (fs) laser-written distributed fiber Bragg gratings (FBGs) under high-temperature conditions up to 1600°C and explores the impact of rapid heat treatment on signal-to-noise ratio (SNR) enhancement. FBGs are essential for reliable optical sensing in extreme temperature environments. Comprehensive tests demonstrate the remarkable performance and resilience of FBGs at temperatures up to 1600°C, confirming their suitability for deployment in such conditions. The study also reveals significant fringe visibility improvements of up to ∼10 dB on a 1-m-long sapphire optical fiber through rapid heat treatment, representing a first-time achievement to the best of our knowledge. …

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Switching Of Control Mechanisms During The Rapid Solidification Of A Melt Pool, Yijia Gu, Jiandong Yuan, Lianyi Chen Oct 2023

Switching Of Control Mechanisms During The Rapid Solidification Of A Melt Pool, Yijia Gu, Jiandong Yuan, Lianyi Chen

Materials Science and Engineering Faculty Research & Creative Works

The Solidification of Alloys is Typically Controlled by Solute Diffusion Due to the Solute Partitioning Happening at the Solid-Liquid Interface. in This Study, We Show that the Switching from Solute Diffusion-Controlled Growth to Thermal Diffusion-Controlled Growth May Happen at the Solidification Front during Rapid Solidification Processes of Alloys Such as Additive Manufacturing using a Phase-Field Model. the Switching is Found to Be Triggered by the Cooling of the Solid-Liquid Interface When It Becomes Colder Than the Solidus Temperature. the Switching Introduces a Sudden Jump of Growth Velocity, an Increase in Solute Concentration, and the Refining of the Resulting Microstructures. All …

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Mechanism Underlying Effect Of Expansive Agent And Shrinkage Reducing Admixture On Mechanical Properties And Fiber-Matrix Bonding Of Fiber-Reinforced Mortar, Kamran Aghaee, Taihao Han, Aditya Kumar, Kamal Khayat Oct 2023

Mechanism Underlying Effect Of Expansive Agent And Shrinkage Reducing Admixture On Mechanical Properties And Fiber-Matrix Bonding Of Fiber-Reinforced Mortar, Kamran Aghaee, Taihao Han, Aditya Kumar, Kamal Khayat

Materials Science and Engineering Faculty Research & Creative Works

Expansive agent (EA) and shrinkage reducing admixture (SRA) are utilized to reduce shrinkage and risk of cracking in concrete. EA compensates shrinkage by initial expansion, and SRA reduces surface tension in the pore fluid. Although EA and SRA effectively reduce shrinkage, they can impair micro-structure of concrete at high contents. The shrinkage reduction effect of EA and SRA is well known; however, there is limited knowledge about their negative effect on microstructure and fiber matrix interfacial transition zone (ITZ). The current study explores the effect of using 10 % CaO-based EA, 2 % SRA, and their combination on mechanical, shrinkage, …

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On The Prediction Of The Mechanical Properties Of Limestone Calcined Clay Cement: A Random Forest Approach Tailored To Cement Chemistry, Taihao Han, Bryan K. Aylas-Paredes, Jie Huang, Ashutosh Goel, Narayanan Neithalath, Aditya Kumar Oct 2023

On The Prediction Of The Mechanical Properties Of Limestone Calcined Clay Cement: A Random Forest Approach Tailored To Cement Chemistry, Taihao Han, Bryan K. Aylas-Paredes, Jie Huang, Ashutosh Goel, Narayanan Neithalath, Aditya Kumar

Materials Science and Engineering Faculty Research & Creative Works

Limestone calcined clay cement (LC3) is a sustainable alternative to ordinary Portland cement, capable of reducing the binder's carbon footprint by 40% while satisfying all key performance metrics. The inherent compositional heterogeneity in select components of LC3, combined with their convoluted chemical interactions, poses challenges to conventional analytical models when predicting mechanical properties. Although some studies have employed machine learning (ML) to predict the mechanical properties of LC3, many have overlooked the pivotal role of feature selection. Proper feature selection not only refines and simplifies the structure of ML models but also enhances these models' prediction performance and interpretability. This …

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Graphite And Dispersant Additives For Battery Paste Compositions, Fatih Dogan, Julian Kosacki Sep 2023

Graphite And Dispersant Additives For Battery Paste Compositions, Fatih Dogan, Julian Kosacki

Materials Science and Engineering Faculty Research & Creative Works

Various graphite additives were incorporated into the positive battery paste composition to compare their effects on the positive active mass utilization of lead-acid batteries. The disclosure is related to battery paste composition for preparing a lead-acid battery plate comprising a graphite additive selected from the group consisting of globular natural graphite, natural flake graphite, expanded flake graphite, and combinations thereof. The disclosure is also related to a battery paste composition comprising a sodium polymethacrylate dispersant. The disclosure is further related to batteries prepared by these battery paste compositions.

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Large-Scale Cascading Of First-Order Fbg Array In A Highly Multimode Coreless Fiber Using Femtosecond Laser For Distributed Thermal Sensing, Farhan Mumtaz, Bohong Zhang, Ronald J. O'Malley, Jie Huang Aug 2023

Large-Scale Cascading Of First-Order Fbg Array In A Highly Multimode Coreless Fiber Using Femtosecond Laser For Distributed Thermal Sensing, Farhan Mumtaz, Bohong Zhang, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research focuses on the performance analysis and characterization of a fiber Bragg gratings (FBGs) array, consisting of 10 first order FBGs inscribed by a femtosecond (FS) laser in a highly multimode coreless fiber. The study evaluates the FBG array's ability to function as a distributed thermal sensing (DTS) platform, with the coreless fiber chosen as the sensing element due to its immunity to dopant migration at high temperatures. The design of a large cascaded first-order FBG array effectively eliminates unwanted harmonic peaks across a wide spectrum range. In contrast, higher-order FBGs introduce limitations due to the overlapping of Bragg …

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Electrosteric Control Of The Aggregation And Yielding Behavior Of Concentrated Portlandite Suspensions, Sharu Bhagavathi Kandy, Narayanan Neithalath, Mathieu Bauchy, Aditya Kumar, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant Aug 2023

Electrosteric Control Of The Aggregation And Yielding Behavior Of Concentrated Portlandite Suspensions, Sharu Bhagavathi Kandy, Narayanan Neithalath, Mathieu Bauchy, Aditya Kumar, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

Portlandite (calcium hydroxide: CH: Ca (OH)2) suspensions aggregate spontaneously and form percolated fractal aggregate networks when dispersed in water. Consequently, the viscosity and yield stress of portlandite suspensions diverge at low particle loadings, adversely affecting their processability. Even though polycarboxylate ether (PCE)-based comb polyelectrolytes are routinely used to alter the particle dispersion state, water demand, and rheology of similar suspensions (e.g., ordinary portland cement suspensions) that feature a high pH and high ionic strength, their use to control portlandite suspension rheology has not been elucidated. This study combines adsorption isotherms and rheological measurements to elucidate the role of PCE composition …

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A Spike-Shaped Anchorage For Steel Reinforced Polymer (Srp)-Strengthened Concrete Structures, Xingxing Zou, Keenan L. Mcburney, Lesley H. Sneed Jul 2023

A Spike-Shaped Anchorage For Steel Reinforced Polymer (Srp)-Strengthened Concrete Structures, Xingxing Zou, Keenan L. Mcburney, Lesley H. Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel reinforced polymer (SRP) composite has recently emerged as an effective and economical solution for strengthening of reinforced concrete (RC) structures. Premature debonding failure of unanchored SRP at low load levels generally governs the performance of RC structures strengthened with externally bonded SRP. Therefore, a novel yet simple spike-shaped anchorage system was proposed in this study to prevent the debonding failure of SRP and to improve the interfacial shear capacity. Experimental investigation through single-lap shear tests of SRP-concrete joints showed that the anchorage system changed the failure mode from composite debonding to fiber rupture. In addition, the anchorage system substantially …

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Calibration Of The Johnson–Cook Model At High Temperatures For An Ultra-High Strength Crnimov Steel, Mario F. Buchely, S. Chakraborty, V. Athavale, Laura Bartlett, Ronald J. O'Malley, D. Field, K. Limmer, K. Sebeck Jul 2023

Calibration Of The Johnson–Cook Model At High Temperatures For An Ultra-High Strength Crnimov Steel, Mario F. Buchely, S. Chakraborty, V. Athavale, Laura Bartlett, Ronald J. O'Malley, D. Field, K. Limmer, K. Sebeck

Materials Science and Engineering Faculty Research & Creative Works

This paper presents a study on the thermo-mechanical behavior of an ultra-high strength CrNiMoV steel at high temperatures and medium strain rates through hot tensile tests. The material was examined in two conditions: as-cast/heat-treated (AC/HT) and as-rolled (AR). Tensile tests were conducted at temperatures of 800,900,1000,1100, and 1200°C, and strain rates of 0.1,1, and 10s−1. Inclusion and porosity analysis was also performed on the tensile specimens. The results revealed that the flow stress decreased by approximately 70% on average from 800°C to 1200°C, while increasing by approximately 32% on average from 0.1s−1 to 10s−1 in strain rate. The elongation exhibited …

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A Strong And Ductile Cobalt-Free Solid-Solution Fe30ni30mn30cr10 Multi-Principal Element Alloy From Hot Rolling, Hans Pommerenke, Jiaqi Duan, Nathan Curtis, Victor Delibera, Adam Bratten, Andrew Hoffman, Mario F. Buchely, Ronald J. O'Malley, Haiming Wen Jul 2023

A Strong And Ductile Cobalt-Free Solid-Solution Fe30ni30mn30cr10 Multi-Principal Element Alloy From Hot Rolling, Hans Pommerenke, Jiaqi Duan, Nathan Curtis, Victor Delibera, Adam Bratten, Andrew Hoffman, Mario F. Buchely, Ronald J. O'Malley, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Most of the Face-Centered Cubic (FCC) Multi-Principal Element Alloys (MPEAs) Developed Thus Far Contain Cobalt. for Many Applications, it is Either required or Beneficial to Avoid Cobalt, Since Cobalt Has Long-Term Activation Issue (For Nuclear Applications), is Expensive, and is Considered a Critical Material. in Addition, FCC Structured Solid-Solution MPEAs Tend to Have Relatively Low Strength. a FCC Solid-Solution Fe30Ni30Mn30Cr10 (At %) MPEA Was Fabricated Via Arc Melting, Followed by Homogenization at 1100 °C for 12 H. the Alloy Was Hot Rolled at 1100 °C with a Total Reduction of Up to 97 %. the Microstructure Was Characterized and Mechanical …

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A Strong And Ductile Cobalt-Free Solid-Solution Fe30ni30mn30cr10 Multi-Principal Element Alloy From Hot Rolling, Hans Pommerenke, Jiaqi Duan, Nathan Curtis, Victor Delibera, Adam Bratten, Andrew Hoffman, Mario Buchely, Ronald O'Malley, Haiming Wen Jul 2023

A Strong And Ductile Cobalt-Free Solid-Solution Fe30ni30mn30cr10 Multi-Principal Element Alloy From Hot Rolling, Hans Pommerenke, Jiaqi Duan, Nathan Curtis, Victor Delibera, Adam Bratten, Andrew Hoffman, Mario Buchely, Ronald O'Malley, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Most of the face-centered cubic (FCC) multi-principal element alloys (MPEAs) developed thus far contain cobalt. for many applications, it is either required or beneficial to avoid cobalt, since cobalt has long-term activation issue (for nuclear applications), is expensive, and is considered a critical material. in addition, FCC structured solid-solution MPEAs tend to have relatively low strength. an FCC solid-solution Fe30Ni30Mn30Cr10 (at %) MPEA was fabricated via arc melting, followed by homogenization at 1100 °C for 12 h. the alloy was hot rolled at 1100 °C with a total reduction of up to 97 %. the microstructure was characterized, and mechanical …

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Engineering Heterogeneous Nucleation During Solidification Of Multiphase Cast Alloys: An Overview, Simon (Semen) N. Lekakh, Jingjing Qing Jul 2023

Engineering Heterogeneous Nucleation During Solidification Of Multiphase Cast Alloys: An Overview, Simon (Semen) N. Lekakh, Jingjing Qing

Materials Science and Engineering Faculty Research & Creative Works

The theory of heterogeneous nucleation was initially developed as a part of condensed matter physics, and later it was used as an important engineering tool to design metallurgical processes. This success has led to wide applications of the theory in metallurgical practice. For example, engineering heterogeneous nucleation in ductile iron has been used to reduce shrinkage defects, suppress cementite formation, and modify the size and shape of microstructural constituencies. This demonstrates how theoretical knowledge could benefit industry practice. This overview aims to summarize the authors' published studies in co-authorship with colleagues and students, which covers different aspects of engineering heterogeneous …

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Nonmonotonic Effect Of Chemical Heterogeneity On Interfacial Crack Growth At High-Angle Grain Boundaries In Fe-Ni-Cr Alloys, Yuchu Wang, Bita Ghaffari, Christopher Taylor, Simon Lekakh, Carlos Engler-Pinto, Larry Godlewski, Yang Huo, Mei Li, Yue Fan Jul 2023

Nonmonotonic Effect Of Chemical Heterogeneity On Interfacial Crack Growth At High-Angle Grain Boundaries In Fe-Ni-Cr Alloys, Yuchu Wang, Bita Ghaffari, Christopher Taylor, Simon Lekakh, Carlos Engler-Pinto, Larry Godlewski, Yang Huo, Mei Li, Yue Fan

Electrical and Computer Engineering Faculty Research & Creative Works

An intermittent pattern is observed in the modeling of interfacial cyclic-loading crack growth at high-angle grain boundaries in ternary Fe-Ni-Cr alloys. Different from conventional wisdom of stress-intensity factor, the abrupt crack advances are found driven by extreme value statistics - namely, the aggregation of atoms with most compressive residual stresses. In addition, inherently non-affine atomic stress fluctuations are discovered, and the fluctuations peak at intermediate level of chemical heterogeneity, causing the fastest crack growth. Implications of such nonmonotonic mechanism in regard to the origin of intermediate-temperature embrittlement phenomena are also discussed.

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Unlocking Road Stability: Machine Learning-Powered Prediction Of Bitumen Distortion Under Traffic Flow Influence, Sabahudin Vrtagic, Milan Dordevic, Fatih Dogan, Muhammed Codur, Mario Hoxha, Edis Softic Jun 2023

Unlocking Road Stability: Machine Learning-Powered Prediction Of Bitumen Distortion Under Traffic Flow Influence, Sabahudin Vrtagic, Milan Dordevic, Fatih Dogan, Muhammed Codur, Mario Hoxha, Edis Softic

Materials Science and Engineering Faculty Research & Creative Works

Road intersections are made of asphalt pavement, a popular road surface material used worldwide. The pavement may suffer deformities and deterioration, resulting in higher maintenance expenses and an elevated likelihood of road accidents, due to factors such as heavy vehicles and environmental variables like temperature and rainfall. To tackle these obstacles, researchers have devised several machine-learning algorithms and optimization techniques. These tools aim to forecast and scrutinize pavement deformation, with the goal of refining pavement design and maintenance approaches, as well as obtaining a more comprehensive comprehension of the factors that impact pavement effectiveness. This paper shows that heavy vehicles …

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Experimental And Machine Learning Studies On Chitosan-Polyacrylamide Copolymers For Selective Separation Of Metal Sulfides In The Froth Flotation Process, Keitumetse Monyake, Taihao Han, Danish Ali, Lana Z. Alagha, Aditya Kumar Jun 2023

Experimental And Machine Learning Studies On Chitosan-Polyacrylamide Copolymers For Selective Separation Of Metal Sulfides In The Froth Flotation Process, Keitumetse Monyake, Taihao Han, Danish Ali, Lana Z. Alagha, Aditya Kumar

Mining Engineering Faculty Research & Creative Works

The froth flotation process is extensively used for the selective separation of valuable base metal sulfides from uneconomic associated minerals. However, in this complex multiphase process, various parameters need to be optimized to ensure separation selectivity and peak performance. In this study, two machine learning (ML) models, artificial neural network (ANN) and random forests (RF), were used to predict the efficiency of in-house synthesized chitosan-polyacrylamide copolymers (C-PAMs) in the depression of iron sulfide minerals (i.e., pyrite) while valuable base metal sulfides (i.e., galena and chalcopyrite) were floated using nine flotation variables as inputs to the models. The prediction performance of …

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Dissolution Rates Of Borophosphate Glasses In Deionized Water And In Simulated Body Fluid, Parker T. Freudenberger, Rebekah L. Blatt, Richard K. Brow Jun 2023

Dissolution Rates Of Borophosphate Glasses In Deionized Water And In Simulated Body Fluid, Parker T. Freudenberger, Rebekah L. Blatt, Richard K. Brow

Materials Science and Engineering Faculty Research & Creative Works

Particles of Borophosphate Glasses with the Nominal Molar Compositions 16Na2O-(24-Y)CaO-YSrO-XB2O3-(60-X)P2O5 (Mol%), Where 0 ≤ X ≤ 60 and Y = 0, 12, and 24, Were Reacted in Deionized Water and in Simulated Body Fluid (SBF) at 37 °C. for the Dissolution Experiments in Water, the PH of the Solution at the Conclusion of the Experiments Increased Systematically, from 2.1 to 9.5, for Y = 0 Glasses When 'x' Increased from 0 to 60. the Reaction Rates over the First 8–24 H of Dissolution in Both SBF and Deionized Water Followed Linear …

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