Metallurgy Commons^™

Surface Chemistry And Adsorption Mechanism Of Orfom® D8 For Cu Depression In Cu-Mo Flotation, Patrick Jeff Mensah

Graduate Theses & Non-Theses

In traditional chalcopyrite-molybdenite (Cu-Mo) flotation separation systems, inorganic depressants such as NaSH and NaCN are used to selectively depress chalcopyrite making it more hydrophilic so molybdenite can be floated and recovered. NaSH and NaCN are highly toxic, have high explosion potential, strong odor, and readily oxidize in air resulting in a high consumption rates. To control oxidation, nitrogen gas, and Nokes reagent are both necessary, making the process even more expensive. In addressing these challenges, attention is fast shifting to disodium carboxymethyl trithiocarbonate (Orfom® D8), a novel organic depressant designed to replace conventional inorganic depressants because it does not easily …

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

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

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 …

Optimizing The Physical Properties Of Biochar For Co2 Adsorption Using Resonant Vibrations, Amirhosein Riahi, Richard Ladouceur

Mining Engineering

Among various Carbon Capture and Sequestration (CCS) technologies, significant emphasis has been placed on biochar as an effective post-combustion CO2 capture method. Biochar demonstrates potential as a technically effective method for stabilizing carbon. However, the efficacy of CCS based on adsorption phenomenon depends on factors such as the CO2 uptake of the adsorbent, kinetic rates, and cyclic adsorption. The study shows that Low-Frequency High Amplitude (LFHA) resonant vibratory mixing improves the physical characteristics and adsorption properties of hemp biochar. According to the results of an analysis of variance (ANOVA), increasing both the mass of biochar and the intensity of resonant …

Computational Modeling Of High Yttrium Refractory High Entropy Alloy Microstructures, Kaleb C. Ryan, Marissa M. Baker

College of Engineering Summer Undergraduate Research Program

Refractory high entropy alloys (RHEAs) are advanced metals made up of five or more principal elements in roughly equal amounts. The microstructural effects of alloying with yttrium as a principal element for RHEAs are currently not well understood. This project compared RHEA microstructures from literature with simulations using the High Entropy Alloy Predicting Software (HEAPS), which computes 10 screening criteria to predict the microstructure of a RHEA composition. The accuracy of HEAPS predictions was assessed by comparing them with experimentally validated microstructures found in literature. A combination of criteria was found to have a 95.8% accuracy rate, and a new …

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 …

Experimental Investigation And Evaluation Of Mechanical Properties And Microstructural Characterization On Chromium Molybdenum Steel Processed Through Laser Based Welding, Rakesh S

Theses and Dissertations

Creep Strength Enhanced Ferritic (CSEF) martensitic modified 9Cr-1Mo (P91) steel is extensively employed in fast breeder nuclear reactors and thermal power plants owing to its superior resistance to thermal fatigue and oxidation corrosion compared with other low-alloy steels. Despite its excellent high-temperature performance, the weldability of this steel remains a critical concern.

Conventional arc welding processes generate excessive heat input and complex thermal cycles, resulting in heterogeneous microstructures, retention of δ-ferrite, and subsequent degradation in service life. In contrast, high energy density beam welding techniques such as laser and electron beam welding offer precise thermal control and minimal heat-affected zones …

Utilization Of Sodium Flame Synthesis For The Formation And Deposition Of Pure Metal Materials For Applications In Additive Manufacturing, Zachariah Wargel

McKelvey School of Engineering Graduate Student Theses & Dissertations

Advanced material classes, such as high temperature alloys, ceramics, and refractory materials have become a key area of focus for expansion in the realm of additive manufacturing. Factors such as high melting points, material homogeneity, and physical properties such as ductility limit the application of popular additive manufacturing methods to these material classes. By utilizing sodium flame synthesis and deposition (SFD) technology, nanoparticle materials can be synthesized via combustion in a laminar co-flow diffusion burner and impacted such that the deposits can be used to manufacture designed components. By using the applicable precursor materials of metal chlorides and elemental sodium …

Effect Of Impurities In Supercritical Co2 Environment On Steel Corrosion Behavior – An Overview, Shilla Rizqi Widianto, Johny Wahyuadi Soedarsono, Rini Riastuti, Badrul Munir

Journal of Materials Exploration and Findings

Carbon capture, utilization, and storage (CCUS) technology is one of the available technologies to reduce presence of greenhouse gasses. Implementation of CCUS technology strongly relates with the CO₂ transportation from the capturing facility to the storage in the geological reservoir. The most economical method for large-scale and long-distance CO₂ transportation is using pipeline in supercritical phase. Moreover, presence of impurities such as water, O₂, SO₂, H₂S, NO₂ may cause detrimental effect towards carbon steel pipeline. This paper intends to provide an initial information for supercritical CO₂ pipeline material selection, which …

Hollow Connecting Rod Thin Wall Austempered Ductile Iron (Twadi) For Manufacturing Light Weight Components, Ricardina Freitas Da Silva, Bambang Suharno, Rianti Dewi Sulamet-Ariobimo

Journal of Materials Exploration and Findings

Efforts made by the automotive industry to reduce energy consumption have encouraged researchers to carry out various studies. One way is to make components lighter by casting thin wall austempered ductile iron (TWADI). Reducing the weight of components such as connecting rods (conrod) will result in lower energy consumption, but provided that these components still meet standards in terms of mechanical properties and microstructure or even exceed them. In this research, design optimization was applied to conrod by making the area I-beam zero mm (hollow), with hope that it can replace conrod Vespa PX-150. While the manufacturing process is divided …

Analysis Risk Based Inspection Api 581 On Lpg Spherical Tank At Pt. Xyz, Sigit Trahmawan, Eddy Sumarno Siradj, Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

Liquified petroleum gas (LPG) spherical tanks are pressure vessel equipment for storing fuel gas products. The high pressure along with the fuel gas inside as flammable and combustible substance means that this equipment might result major accident hazard such as explosion, fires and environmental pollution. This study is aimed calculated and mitigate risk on 500 metric ton capacity LPG spherical tank using Risk-based inspection (RBI) analysis method that makes risk as its foundation. This RBI method uses quantitative analysis referring to API 581 to determine the risk of LPG Spherical Tank by determining the probability of failure (PoF) and the …

Settingsorder Article Reprints Open Accessarticle A Model To Account For The Effects Of Load Ratio And Hydrogen Pressure On The Fatigue Crack Growth Behavior Of Pressure Vessel Steels, Ashok Saxena, Kip O. Findley

Mechanical Engineering Faculty Publications and Presentations

A phenomenological model for estimating the effects of load ratio R and hydrogen pressure P_H2 on the hydrogen-assisted fatigue crack growth rate (HA-FCGR) behavior in the transient and steady-state regimes of pressure vessel steels is described. The "transient regime" is identified with crack growth within a severely embrittled zone of intense plasticity at the crack tip. The "steady-state" behavior is associated with the crack growing into a region of comparatively lower hydrogen concentration located further away from the crack tip. The model treats the effects of R and P_H2 as being functionally separable. In the transient …

Computational Alchemy: Pioneering Spintronic, Thermoelectric, And Optoelectronic Materials Design Through First-Principles Calculations And Machine Learning, Eesha Sanjay Andharia

Graduate Theses and Dissertations

Intelligent materials discovery and design plays a pivotal role in advancement of spintronics, optoelectronics and thermoelectric devices and technology. In this study, we investigate three types of materials using first principles calculations. First, the structural, electronic, and magnetic properties of CrTiCoZ (Z = Al, Si) equiatomic quaternary Heusler alloys were investigated. CrTiCoAl compound was found to exhibit a half metallic ferromagnetic structure and Curie temperature above room temperature, which makes it an ideal candidate for magnetic tunnel junction, the basic building block of Spintronic devices. Second, we use Green’s function to obtain the finite temperature phonons by including quartic anharmonicity …

Modeling Study Of Si3N4 Waveguides On A Sapphire Platform For Photonic Integration Applications, Diandian Zhang, Shui-Qing Yu, Gregory J. Salamo, Richard A. Soref, Wei Du

Electrical Engineering and Computer Science Faculty Publications and Presentations

Sapphire has various applications in photonics due to its broadband transparency, high-contrast index, and chemical and physical stability. Photonics integration on the sapphire platform has been proposed, along with potentially high-performance lasers made of group III–V materials. In parallel with developing active devices for photonics integration applications, in this work, silicon nitride optical waveguides on a sapphire substrate were analyzed using the commercial software Comsol Multiphysics in a spectral window of 800~2400 nm, covering the operating wavelengths of III–V lasers, which could be monolithically or hybridly integrated on the same substrate. A high confinement factor of ~90% near the single-mode …

Development Of Iii-V And Iv Epitaxy On Sapphire Technology, Emmanuel Wangila

Graduate Theses and Dissertations

This research presents comprehensive insights into the epitaxial growth of germanium (Ge) on c-plane sapphire substrates using molecular beam epitaxy (MBE). The direct growth of Ge on sapphire typically yields three-dimensional (3D) Ge islands with diverse growth directions, multiple primary domains, and twinned crystals. However, incorporating a thin AlAs nucleation layer proves instrumental in enhancing surface and material quality. With a 10 nm AlAs layer, the achieved surface exhibits improved characteristics, including a smoother surface, single epitaxial orientation, sharper rocking curve, and a single domain. This study surpasses previous works by achieving a single primary domain and reducing twinning. Furthermore, …

Modeling Powder Spreadability In Powder-Based Processes Using The Discrete Element Method, Austin T. Sutton, M. Hossein Sehhat, Ming C. Leu, Joseph W. Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Powder-bed fusion (PBF) processes refer to a subset of Additive Manufacturing (AM) techniques where powder is spread on the build-plate before melting (by a laser or electron beam). While PBF processes are attractive due to their ability for realizing complex structures that are either difficult or impossible to create through conventional means, the parts fabricated with these techniques can exhibit defects such as pores, inclusions, and excessive surface roughness. To minimize these defects, much research has been dedicated towards process maturation by optimizing laser or electron beam parameters. However, these developmental efforts typically do not address the recoating process where …

Pulsing-Induced Healing Of A Surface Crack Of A Nickel-Based Alloy, Liwei Wang, Mingming Quan, Zhen Tan, Ming Liu, Dianlong Wang, Xiao Yang, Ying Liu, Yaning Mao, Zhimin Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

In this work, we demonstrate the feasibility of applying electric pulses to heal surface cracks on nickel-based alloy GH4169 under compressive load. There exists an incubation time for the onset of the healing of a crack, which is associated with local temperature at the crack tip. The crack size decreases with increasing the pulsing time at a constant healing rate prior to complete healing of the crack. Increasing compressive load accelerates the healing process. The electric pulsing leads to the formation of an influential zone surrounding the crack with the finest grain sizes in the healed crack and the coarsest …

Extreme Value Statistics Analysis Of Process Defects In Additive Manufacturing Materials, Ayorinde E. Olatunde, Kristen Hernandez, Austin Ngo, Arafath Nihar, Thomas G. Ciardi, Rachel Yamamoto, Pawan K. Tripathi, Roger H. French, John J. Lewandowski, Anirban Mondal

Faculty Scholarship

Fatigue and fracture studies focused on process defects that occur in Additive Manufacturing (AM) materials have shown that defect populations possess features which are better measured with extreme value statistics (EVS). In AM alloys, defect occurrences increase with material volume. This situation facilitates the need to model process defects in the path of fatigue crack growth with suitable statistical tools, such as EVS, which is more cost-effective when compared to destructive experiments. The application of EVS on defect space features helps determine the difference in defects present on fracture surfaces. As the fatigue quality of any material depends on its …

Metallurgical Impact Of Switching From Hammer Units To Hydraulic Presses For Forging, Cole Hawker, Jacob Reed

Materials Engineering

Carlton Forge Works (CFW) is evaluating the retirement of its hammer units in favor of hydraulic presses to address safety concerns in forging aerospace components. This paper investigates the metallurgical implications of this transition, emphasizing the importance of superior microstructures and meeting industry standards and customer requirements. The alloys in question are Titanium-6Al-4V (Ti64) and Inconel 718 (INCO 718), which comprise a majority of CFW’s production. Ti64's high specific strength and thermal stability make it ideal for aerospace applications, while INCO 718 is recognized for superior high-temperature creep performance. Defects like freckles and white spots in INCO 718 are analyzed …

Photodegradation Of Microplastics Through Nanomaterials: Insights Into Photocatalysts Modification And Detailed Mechanisms, Yiting Xiao, Yang Tian, Wenbo Xu, Jun Zhu

Biological and Agricultural Engineering Faculty Publications and Presentations

Microplastics (MPs) pose a profound environmental challenge, impacting ecosystems and human health through mechanisms such as bioaccumulation and ecosystem contamination. While traditional water treatment methods can partially remove microplastics, their limitations highlight the need for innovative green approaches like photodegradation to ensure more effective and sustainable removal. This review explores the potential of nanomaterial-enhanced photocatalysts in addressing this issue. Utilizing their unique properties like large surface area and tunable bandgap, nanomaterials significantly improve degradation efficiency. Different strategies for photocatalyst modification to improve photocatalytic performance are thoroughly summarized, with a particular emphasis on element doping and heterojunction construction. Furthermore, this review …

Development Of 485 Mpa Class High Strength Low Alloy Steel For Power Plant Infrastructures, Agung Baskoro, Rini Riastuti

Journal of Materials Exploration and Findings

Currently, Indonesia is progressing to build 35,000 MW of power plants, which will increase the demand for materials, especially steel. One of these power plants is fossil fuel-based, which generates not only electricity but also flue gas containing sulfur that may cause corrosion to power plant infrastructure such as chimney or boiler areas. In addition, apart from being resistant to corrosion in sulfuric and hydrochloric acid conditions, the steel used in power plant infrastructure must also have good strength, toughness, and weldability. Therefore, the present paper describes about steel development for power plant applications that has not only corrosion resistance …

Engineering Composite Gridlines For Improved Solar Module Reliability, Andre Chavez

Electrical and Computer Engineering ETDs

Renewable energy sources, such as solar power, are rapidly expanding worldwide to meet increased energy demands. However, these sources are exposed to challenging environmental stressors, such as extreme wind, heavy snow loads, and hailstorms that can cause irreversible damage to the crystalline semiconductor solar cells. Today, single crystalline silicon solar cells dominate the market, and our work is focused on improving their reliability against environmental stressors. One of the main degradation mechanisms caused by environmental stressors is cell cracks. These microcracks can go virtually undetected and lead to reduced power output from solar modules over time. To solve this engineering …

Characterization Of Chopped Carbon Fiber Reinforced Composites Produced Using Fused Deposition Modeling, Jonathon Tran, Rachel Shubella

Student Research Symposium

Fused deposition modeling (FDM) is an additive manufacturing (AM) process which can create parts with complex geometries in their final shape without need for additional specialized tools or devices. The FDM process builds parts by adding material layer by layer only where it is needed, saving energy, costs, production time for complex parts, and minimizing waste. Fiber reinforcement can significantly enhance the mechanical properties of a polymer material and depends significantly on the fiber length distribution and fiber orientation distribution of the final part. In this research, we investigated the various infill patterns of FDM printed Markforged onyx which is …

Review Of Cyclic Voltammetry Measurements For Uranium In Flinak Molten Salt, Jackson Ivory

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The electrochemical behavior of uranium FLiNaK molten salts is explored, focusing on cyclic voltammetry (CV) as a powerful tool for redox characterization and diffusion studies. Through a comprehensive review of recent research, the study highlights the significance of CV in understanding electrode kinetics, material compatibility, and process optimization in molten salt environments. The findings underscore the potential of FLiNaK molten salt reactors in advancing nuclear energy technologies, fuel processing, and waste management strategies. Collaborative interdisciplinary efforts are emphasized to address challenges and accelerate innovation in electrochemical methods for nuclear applications.

An Overview Of How To Measure The Kinetic Properties Of An Anode Material For The Chlorine Evolution Reaction, Cameron Vann

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The process of generating chlorine gas using electrolysis in aqueous systems is well established. However, a new process requires chlorine to be generated at high temperatures using molten salt. This harsh environment requires a new study of anode materials for the chlorine evolution reaction. Anode materials can be compared by their kinetic parameters, the transfer coefficient α and the exchange current i0. The basic theory of these properties as they relate to the chlorine evolution reaction has been detailed and an analysis method for finding these effective parameters has been shown and demonstrated.

Electrical Resistance Tomography Measurements In Column Flotation Of Pure Hydrophobic And Hydrophilic Systems, Vimeipha Vilayphone

Graduate Theses & Non-Theses

Column flotation was phenomenologically investigated with Electrical Resistance Tomography (ERT) as an uninterrupted instrument to measure gas holdup. Two-phase tests were performed to use the measurements for examining gas dispersion. Results were found to duplicate the findings in a previous thesis. With confidence attained in experimental procedures, three-phase tests were then performed to compare gas holdup with hydrophobic and hydrophilic solids. Hydrophobic solids included talc as well as dolomite with dodecyl amine (DDA) collector. Hydrophilic solids included dolomite as well as talc with carboxymethyl cellulose (CMC) depressant. Variables throughout the research included frother concentration and sparger size. Results showed gas …

Process Intensification For Rare Earth Elements Adsorption By Resonant Vibratory Mixing, Oluwatosin Adebayo, Richard Ladouceur, Zainab Nasrullah

Graduate Theses & Non-Theses

The adsorption capacity for six rare earth elements (Lanthanum, Terbium, Neodymium, Dysprosium, Praseodymium, and Holmium) by biochar produced from hemp feedstock was investigated. An innovative approach to enhancing the adsorption of rare earth elements using biochar was studied and investigates the potential of resonant vibratory mixing (RVM) as a process intensification method compared to conventional mechanical mixing for the adsorption process. Hemp hurds as source of biomass was pyrolyzed to produce biochar at a temperature of 4500C for 60 minutes. The biochar was characterized by FTIR (Fourier Transform Infra-red), SEM (Scanning Electron Microscopy), Surpass 3 Electrokinetic solid surface analyzer, and …

Synthesis Of Bimetallic Nickel And Cobalt Phosphide Nanostructures For Electrocatalysis, Sarah Meixin York

Graduate Theses and Dissertations

Transition metal phosphides have become a new class of materials to be considered as promising catalysts for a number of applications including electrochemical hydrogen evolution (HER). Electrocatalysis in hydrogen evolution is a heavily studied field due to the increasing desire to develop more efficient and more cost-effective catalysts for clean hydrogen production. This project develops a chemical approach to synthesizing bimetallic cobalt-nickel phosphide nanostructures for their use in HER. The synthesis is accomplished by thermal decomposition of the metal precursors in the presence of carbon monoxide (CO) and trioctyl phosphine (TOP). The resulting nanostructures were characterized using transition electron microscopy …

Tin-Silver As A Novel Biodegradable Metallic Biomaterial, Charley Goodwin

All Dissertations

The Essure device is a non-hormonal, minimally-invasive, permanent female sterilization implant, removed from the market due to an increase in adverse events, hypothesized to be caused by corrosion of the Sn-Ag component of the implant. The goals of this dissertation were to first develop implant retrieval methods for Essure devices and surrounding tissue, documenting signs of degradation and metallic degradation products, then to characterize the electrochemical behavior of Sn-Ag in biologically representative environments and finally, to assess the biological interaction of Sn-Ag. Retrieval analyses developed successful methods, qualifying the degree of corrosion, primarily of the Sn-Ag component and finding Sn …