Metallurgy Commons^™

Mesoscale Modeling And Machine Learning Studies Of Grain Boundary Segregation In Metallic Alloys, Malek Alkayyali

All Dissertations

Nearly all structural and functional materials are polycrystalline alloys; they are composed of differently oriented crystalline grains that are joined at internal interfaces termed grain boundaries (GBs). It is well accepted that GB dynamics play a critical role in many phenomena during materials processing or under operating environments. Of particular interest are GB migration and grain growth processes, as they influence many crystal-size dependent properties, such as mechanical strength and electrical conductivity.

In metallic alloys, GBs offer a plethora of preferential atomic sites for alloying elements to occupy. Indeed, recent experimental studies employing in-situ microscopy revealed strong GB solute segregation …

Point Heat Source Correlation To Microstructural Evolution In Advanced Manufacturing, Mark Anderson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Although there are different ways that advanced manufacturing can be performed, the use of single-point heat sources has become the standard to control a final product’s properties. It is imperative to understand how the heat source used in the different advanced manufacturing processes affect the microstructure of interest. The intimate relationship between the heat source and microstructure allows for controlling and tailoring a part’s properties. Utilizing different microstructural analysis, the cross-correlation of various point heat sources to developed microstructure was conducted in this dissertation.

Laser powder bed fusion allows for unique print-to-part protocols, but the dynamics of the process makes …

A Guide To Fifty Years Of Research At Montana Tech: Part 2 The Treatment Of Electroplating And Electromachining Metal Hydroxide Sludge For The Recovery Of Metal Values [See Also Part 1), Larry G. Twidwell

Metallurgy

ABSTRACT and FORWARD

The treatment and recovery of metal species from hydrometallurgical solutions and wastewater solids has been and continues to be an important research topic. This presentation includes a guide to the literature with a summary discussion of the research conducted at Montana Tech in the Department of Metallurgical and Materials Engineering during the 1984-2001 period. A previous presentation (Part 1) focused on the removal of arsenic, selenium, and other species by hydrometallurgical processes and the formation of environmentally stable disposable products. This guide is available at the reference presented above.

This following presentation (Part 2) is based on …

A Guide To Fifty Years Of Research At Montana Tech: Part 1-The Treatment Of Arsenic, Selenium, Thallium, Metal Bearing Solutions And Waste Solids, Larry G. Twidwell

Metallurgy

ABSTRACT and FORWARD

The removal of arsenic, selenium, and metal species from hydrometallurgical solutions and wastewaters has been and continues to be an important research topic. This presentation includes a discussion of the research conducted at Montana Tech in the Department of Metallurgical and Materials Engineering during the past fifty years. The discussion is focused on removal of arsenic by co-precipitation with Fe(III) and Fe(II), co-precipitation with Fe(III) and Al(III), reduction using elemental iron; the removal of selenium by elemental iron and catalysed iron; and the removal of cadmium, copper, nickel, zinc by co-precipitation with Fe(III) and Al(III).

This presentation …

Effects Of Tempering Temperature On Gas Turbine Fan Cases, Seth Utter

Honors Scholar Theses

The project aimed to investigate the effects of tempering temperature on metals used for gas turbine engine fan cases as a major relevant concern is containing blades in during blade-out events. There are three ways to accomplish this: using a thicker metal, incorporating different materials into the case, or heat treating the metal. This project focused on the third solution: reviewing the impact toughness and hardness of fractured samples and their equivalent ductile-to-brittle transition shear faces. Given its availability, 1045 steel, as opposed to aerospace grade metals, was used for in-house testing. The data obtained from these experiments were then …

Mechanical Characterization Of Additively Manufactured Alloys Compared To Their Wrought Counterparts, Laith A. Alqawasmi

Mechanical Engineering ETDs

Additive manufacturing is a method of manufacturing based on building parts layer by layer, allowing for more control over shape of the product, therefore reducing machining costs, reducing material waste, faster production times and the ability to build complex engineering design that other manufacturing technologies won’t be able to produce. This research is on the tensile and indentation testing (following ASME standards) of 3D printed Ti-6Al-4V and Inconel 718 built by powder-based direct energy deposition technology. Ti-6Al-4V is an attractive material for the aerospace and aviation industry, and Inconel 718, a nickel-chromium based superalloy, is an attractive material for usage …

Timeline - History Of The Metallurgy / Mineral Processing Programs (1900-2022), Jerome Downey, Larry G. Twidwell

Metallurgy

No abstract provided.

History Of The Metallurgy / Mineral Processing Programs (1900-2022), Jerome Downey, Larry G. Twidwell

Metallurgy

No abstract provided.

Treatment Of Arsenic-Bearing Minerals And Fixation Of Recovered Arsenic Products: An Updated Review, Larry G. Twidwell

Metallurgy

Mineral processing and extractive metallurgical operations have created and are creating appreciable arsenic bearing wastewater and waste solid products that have to be handled, treated for recycle, or treated for environmentally safe disposal. At present there are intense research and operational activities being conducted to provide the best viable processing procedures to ensure that the mineral processing and extractive metallurgical industries are profitable and environmentally secure. The focus of this presentation is on the element arsenic, even though many other deleterious elements may also be present in ores and concentrates. Numerous base metal resources contain arsenic bearing minerals, especially resources …

Physics-Based Crystal Plasticity Model For Predicting Microstructure Evolution And Dislocation Densities, Juyoung Jeong

LSU Doctoral Dissertations

This work presents three different studies investigating plastic deformation mechanisms in metals and alloys using crystal plasticity finite element (CPFE) modeling. The first study presents a new nonlocal crystal plasticity model for face-centered cubic single crystals under heterogeneous inelastic deformation. The model incorporates generalized constitutive relations that incorporate the thermally activated and drag mechanisms to cover different kinetics of viscoplastic flow in metals and describes the plastic flow and yielding of single-crystals using dislocation densities. The model is compared to micropillar compression experiments for copper single crystals and clarifies the complex microstructural evolution of dislocation densities in metals. The second …

Use Of Electrochemical Techniques And Statistical Analysis To Investigate The Pitting Probability Of Copper, Sina Matin

Electronic Thesis and Dissertation Repository

The development of a safe permanent disposal plan is essential for the long-term disposal of used fuel bundles. Nuclear Waste Management Organization (NWMO) has been investigating the deep geologic disposal of nuclear waste which offers the optimum passive safety system with a negligible probability of release of radionuclides into the environment.

The proposed used fuel containers (UFC) for the permanent disposal of high-level nuclear waste in Canada is comprised of a carbon steel vessel coated with a 3 mm corrosion-resistant copper layer deposited using a combination of electrodeposition and cold spray deposition. Although copper is often considered to be thermodynamically …

Atomistic Simulation Studies Of Thin Film Growth And Plastic Deformation In Metals And Metal/Ceramic Nanostructures, Reza Namakian

LSU Doctoral Dissertations

Despite the significant improvements in manufacturing and synthesis processes of metals and ceramics in the past decades, there are still areas in which the procedure is still frequently more of an art or skill rather than a science. Therefore, systematic and combined experimental and computational studies are required to facilitate the development of techniques that offer thorough understanding of the events taking place during manufacturing and synthesis processes. With regard to these issues, it is paramount to address microscale characterizations and atomic scale understanding of the events during fabrication processes. One of the focuses of this study is unraveling fundamental …

Effect Of Austenization And Repeated Quenching On The Microstructures And Mechanical Properties Of Wear-Resistant Steel, Yanuar Nugraha, Myrna Ariati Mochtar

Journal of Materials Exploration and Findings

This study was focused on determining the effect of repeated austenitization and quenching on mechanical properties and microstructure. The experiment was carried out in a rolled quencher facility with a heat treatment process of one to two times, with parameters of an austenizing temperature of 9500C and quenching at a temperature of 8500C with pressurized water media. Testing of specimens, including microstructure observations and hardness testing. The repeated heat treatment process showed an increase in hardness of 0.79% on one-time repeated heat treatment and 1.65% on two repeated heat treatments. This occurs due to the presence accompanied by refinement of …

The Effect Of Graphite And Activated Carbon As Dispersed Particle In Base Fluid As Quench Medium On The Hardness Of S45c Carbon Steel, Wahyuaji Narottama Putra, Danika Aprilia Somadinata, Ghiska Ramahdita

Journal of Materials Exploration and Findings

Adding a solid particle dispersion into a base fluid could increase its thermal conductivity, hence increasing the heat transfer characteristics. One example of this thermally enhanced fluid is in heat treatment industry as quench medium. By controlling the amount of the dispersed particle, the cooling rate of the quench medium can be altered, and could affect steel hardness after heat treatment. In this research, the dispersed particle used was commercially available graphite and activated carbon particle. As for the base fluid, distilled water and common engine oil were compared. The concentration of the dispersed particle was 0.1, 0.3, 0.5 weight …

Characterization Of Virgin, Re-Used, And Oxygen-Reduced Copper Powders Processed By The Plasma Spheroidization Process, M. Hossein Sehhat, David Perez-Palomino, Connor Wiedemeier, Tristan Cullom, Joseph William Newkirk

Mathematics and Statistics Faculty Research & Creative Works

Fabrication of parts with high mechanical properties heavily depend on the quality of powder deployed in the fabrication process. Copper powder in three different powder types were spheroidized using radio-frequency inductively coupled plasma (ICP) spheroidization process (TekSphero-15 system). The characterized powders include virgin powder as purchased from the powder manufacturer, powder used in electron beam powder bed fusion (EB-PBF) process, and reconditioned powder, which was used powder that underwent an oxygen-reduction treatment. The goal of spheroidizing these powder types was to evaluate the change in powder morphology, the possibility of enhancing the powder properties back to their as-received conditions, and …

A Study On The Impact Of Silicon And Manganese On Peritectic Behavior In Low Alloy Steels Assisted By Mold Thermal Mapping Technology And Shell Growth Measurements, Damilola Balogun, Muhammad Roman, Rex E. Gerald, Laura Bartlett, Jie Huang, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Non-Uniform Shell Growth Commonly Caused by the Peritectic Transformation in Low Carbon and Low Alloy Steels Has Been Directly Correlated with Mold Thermal Maps using a Mold Immersion Test into a Molten Steel Alloy. Mold Thermal Maps Were Obtained by Performing Real-Time Temperature Measurements with Optical Fibers Embedded 1 Mm from the Mold Working Surface. Shell Growth Measurements Were Obtained by 3D Optical Scanning of the Recovered Steel Shell Following Immersion Testing. the Effects of Silicon and Manganese on the Shell Growth and Mold Temperature Maps Have Been Examined in Relation to the Peritectic Transformation for Varying Carbon Contents. Results …

Residual Stress Distribution, Distortion, And Crack Initiation In Conventional And Intensive Quench Practices, Kingsley Tochukwu Amatanweze, Mario F. Buchely, Viraj Ashok Athavale, Laura Bartlett, Ronald J. O'Malley, Toshi Suzuki

Materials Science and Engineering Faculty Research & Creative Works

This study evaluates the effect of two different quench practices on distortion, sensitivity to quench cracking, development and distribution of residual stress, microstructural uniformity, and hardenability of standardized test castings. Navy C-rings made of AISI 4340 were quenched in this experiment. Some rings were quenched in a conventional draft tube immersion quench bath, and others were quenched in an intensive quench spray system to compare with the results from the conventional immersion quench bath. The rings were measured with a coordinate measuring machine, for distortion and flatness, before and after quenching. Hardness profiles of the quenched rings showed through hardness …

Microstructure Evolution And Austenitic Grain Refinement Of Ti-Modified High Mn Steels During Solution Annealing Heat Treatment, Abhinav Karanam, Arnab Sarkar, Erik Nenzen, Viraj Ashok Athavale, Mark Watson, Laura Nicole Bartlett, Lukas Bichler

Materials Science and Engineering Faculty Research & Creative Works

Austenitic high manganese (Mn) steels are often used in harsh environments due to their high toughness and wear resistance. Heat treatments are performed to engineer the microstructure of the steels and optimize their performance for the desired service conditions. This study investigated the effect of titanium (Ti) and heat treatment on the microstructure of cast high Mn steel (HMS) alloys. The results reveal that Ti addition contributed to grain refinement in the as cast and heat-treated conditions. In-situ observation of microstructure evolution up to 1125 °C confirmed the stability of precipitated TiC particles, while revealing a new mechanism of grain …

Effect Of Sc On Recrystallization Resistance Of Aa7050, Keaton Schmidt

Dissertations, Master's Theses and Master's Reports

The extrusion process involves high temperatures and strains that can result in undesirable microstructures, especially along the surface. Extruded alloys tend to exhibit surface recrystallization during heat treating at regions of higher strains, which can lead to reduced fatigue strength and corrosion resistance. By adding Sc to AA7050, nano-sized dispersoids are formed with Sc cores and Zr shells that restrict recrystallization more than the base alloy that only utilizes Zr. Billets with varying Sc content and a control with only Zr were cast, and extrusions were made in order to compare surface microstructures at varying strains in the as-extruded and …

Cascaded Sapphire Fiber Bragg Gratings Inscribed By Femtosecond Laser For Molten Steel Studies, Dinesh Reddy Alla, Deva Prasad Neelakandan, Farhan Mumtaz, Rex E. Gerald, Laura Bartlett, Ronald J. O'Malley, Jeffrey D. Smith, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research reports a distributed fiber optic high-temperature sensing system tailored for applications in the steel industry and various other sectors. Recent advancements in optical sensor technology have led to the exploration of sapphire crystal fibers as a solution for sensing in harsh environments. Utilizing a femtosecond (fs) laser, cascaded fiber Bragg gratings (FBGs) were meticulously fabricated within a multimode sapphire optical fiber. These FBGs endowed the system with distributed sensing capabilities and underwent rigorous testing under extreme temperatures, reaching up to 1,800 °C. The study delves into the investigation of the FBG reflection spectrum, facilitated by the development of …

Compositional Modifications To Alter And Suppress Laves Phases In Alxcrmotayti Alloys, Austin E. Mann, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

Herein, the Development of Refractory Complex Concentrated Alloys in the Al–Cr–Mo–Ta–Ti Alloy System is Reported. Alloys with Modified Al and Ta Concentrations Are Designed using CALPHAD Tools and Produced Via Arc Melting and Characterized in Both As-Cast and Annealed Forms. Properties of the Alloys, Nature of the Microstructures, and Phase Transformation Behavior Are Described Via X-Ray Diffraction, Microstructural Characterization, Microhardness, and Differential Scanning Calorimetry. Two Alloys, Namely, Al0.25CrMoTa0.8Ti and Al0.75CrMoTa0.8Ti, Are Represented by a Body-Centered-Cubic Matrix Phase after Annealing, along with a Secondary Cr–Ta Laves Phase of the C15 and C14 Polytypes, respectively. in As-Cast and Annealed Forms, the Al0.75CrMoTa0.45Ti …

Investigation Of Oxidation And Corrosion Resistance Of Ni-Based Alloys And Stainless Steels Under Co2 Environments At Elevated Temperatures, Spencer Roy Fultineer

Graduate Theses, Dissertations, and Problem Reports

High mechanical strength integrity, high robustness towards oxidation, and high resistance to carburization under CO2 environments at elevated temperatures are usually required for metallic systems that are employed for power generation. INCONEL 625 is a nickel-based superalloy that started development in the 1950s. This material was designed with the distinct purpose of use in high-temperature and high-pressure systems. While various materials possess the physical properties to handle these conditions, the creation of IN625 addresses the need for a material to withstand the highly corrosive properties of these kinds of environments. In order to evaluate the oxidation and corrosion resistance of …

Design And Fabrication Of A High-Performance Heat Exchanger Using An Optimized Three-Dimensional Surface Structure Through Additive Manufacturing, Seth T. Waters

Electronic Theses and Dissertations

A heat exchanger is a device used to transfer thermal energy between two intertwining fluid pathways. In this study, the design of a novel heat exchanger is proposed using functional gradient double gyroid structure. The complex internal geometries of the gyroid structure significantly increases the surface area to volume ratio, and potentially could expressively improve efficiency of the heat transfer. The proposed idea provides a new approach for the design of a high-efficiency heat exchanger. In order to fabricate the complex structured heat exchanger system additive manufacturing is adapted instead of traditionally subtractive manufacturing techniques or casting. The prototypes of …

Investigation Of Microstructurally Dependent Mechanical Properties Of Cold Sprayed Copper Using Correlative Microscopy, Quintin Otto

UNF Graduate Theses and Dissertations

This project employs multi-instrument materials characterization to analyze material made with the “Cold Spray” additive manufacturing process. Cold spray is an emerging additive manufacturing technique with unique benefits resulting from its low temperature adhesion process induced by plastic deformation. Metallic powder collides at high speeds creating three dimensional materials and coatings without the need for melting. Copper cold sprayed specimens were analyzed using a series of imaging techniques to characterize the microstructure at varying levels of detail and magnification. Scanning electron microscopy and electron back scattered diffraction were paired with microhardness testing to generate a correlative comparison between microstructure and …

Machine Learning Strategies For Potential Development In High-Entropy Driven Nickel-Based Superalloys, Marium Mostafiz Mou

MSU Graduate Theses

In this study, I developed Deep Learning interatomic potentials to model a multi-phase and multi-component system of Ni-based Superalloys. The system has up to three major phase constituents, namely Gamma, Gamma Prime, and Transition-metal rich Carbide. I utilized invariant scalar-based and/or equivariant, tensor-based neural network (NN) approach as implemented in DEEPMD, NEQUIP/ALLEGRO codes, respectively, and Moment Tensor Potential (MTP). For the training and validation sets, I employed the ab-initio molecular dynamics (AIMD) trajectory results and ground state DFT calculations, including the energy, force, and virial database from highly diverse compositions, temperatures, and pressures following a “High Entropy Strategy.” The Deep …

Recycling Metal Chips Into Usable Materials, Alex Mortensen, Ben Mortensen

Williams Honors College, Honors Research Projects

This report entails the scope, design considerations, and plans for creating a metal chip converter into metal briquettes. The construction is a set of machines with multiple processes to make the conversion happen. The process includes washing fine metal chips, drying them off, compressing them, and melting them down into usable briquettes. This project is intended to make a simple process to recycle metal chips into usable material for reuse. The project's objective is to reduce the costs of storage and recycling waste by offering a solution to recycle it into materials the shop can reuse.

Elastoplastic Quasi-Static And Impact Load Response Of Steel Structure Sub-Assemblage With Cfrp Strips, Ali Al Aloosi, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

Presented in this paper is the outcome of an experimental investigation of the elastoplastic quasi-static and impact load response of a steel sub-assemblage constructed using a pair of hollow square section members with or without Carbon Fiber Reinforced Polymer (CFRP) strips. The sub-assemblage consists of a long structural member welded to a short member, thus representing a typical combination of a column and a beam on the face of a multi-story steel building frame. The column is subjected to a lateral quasi-static or impact load. Tests are conducted on four separate steel sub-assemblages. The first two tests are conducted with …

An Updated Analytical Method For Predicting The Bracing Behavior Of Z-Purlin Supported Standing Seam Diaphragm Systems, Michael W. Seek

Engineering Technology Faculty Publications

Roof systems utilizing Z-purlins as a secondary member supporting a standing seam panel system are used extensively by the metal building industry. The Z-purlins rely on the diaphragm action in the standing seam panel system to provide lateral support and transfer forces to anchorages. The behavior of the standing seam system is highly nonlinear making prediction of the interaction between the Z-purlin and the standing seam system difficult. To better understand the behavior of the interaction between the purlins and the panel system, a series of non-linear shell finite element models were developed based on the test results of simple …

Cold-Formed Steel Strength Predictions For Combined Bending And Torsion, Yu Xia, Robert S. Glauz, Benjamin W. Schafer, Michael Seek, Hannah B. Blum

Engineering Technology Faculty Publications

Locally slender cross-section members, such as cold-formed steel Cee and Zee sections, are susceptible to significant twisting and high warping torsion stresses. Torsion considerations are complicated by whether it is derived as a first-order effect from loading or a second-order effect from instability. The current design for combined bending and torsion interaction has some limitations, including only considering the first yield in torsion and ignoring the cross-section slenderness in torsion. Previous work has derived a simple uniform equation to predict the bimoment capacity and two bimoment strength curves for local and distortional buckling under torsion only. This work is extended …

Characterization Of Virgin, Re-Used, And Oxygen-Reduced Copper Powders Processed By The Plasma Spheroidization Process, M. Hossein Sehhat, David Perez-Palomino, Connor Wiedemeier, Tristan Cullom, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

Fabrication of parts with high mechanical properties heavily depend on the quality of powder deployed in the fabrication process. Copper powder in three different powder types were spheroidized using radio-frequency inductively coupled plasma (ICP) spheroidization process (TekSphero-15 system). The characterized powders include virgin powder as purchased from the powder manufacturer, powder used in electron beam powder bed fusion (EB-PBF) process, and reconditioned powder, which was used powder that underwent an oxygen-reduction treatment. The goal of spheroidizing these powder types was to evaluate the change in powder morphology, the possibility of enhancing the powder properties back to their as-received conditions, and …