Metallurgy Commons^™

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 …

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 …

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 …

Mechanical Characterization And Evaluation Of Additively Manufactured Titanium 5v-5mo-5al-3cr Alloy, Zachary Casias

Mechanical Engineering ETDs

Ti-5V-5Mo-5Al-3Cr (Ti-5553) is a near beta titanium alloy commonly used in aerospace applications. It is currently being explored for additive manufacturing (AM), but the fatigue behavior of this AM alloy needs to be well-understood for adoption in aerospace applications. The present work examines the tensile and fatigue behavior of LPBF manufactured Ti-5553. The effect of post-print heat treatments, effects of surface roughness, and print defects on the mechanical properties of AM Ti-5553 were also evaluated. Fatigue lives of as-LPBF and BAA material are nearly identical, and both are far below the fatigue lives of conventionally manufactured Ti-5553 of 350 MPa. …

Thermogravimetric Analysis Of High & Low Alloy Steel, Clark Nguyen

Undergraduate Research Conference at Missouri S&T

Oxidation phenomena play a critical role in high temperature metallurgical processing and the performance during life cycle of components made of both high and low alloy steels. Therefore, the development of a precise experimental methodology to quantify oxidation processes is critically important. This report summarizes my experimental study of the oxidation behavior of high and low alloy steel, including kinetics of surface oxide layer formation and spallation. The focus of study was in determining the complex interactions between alloying elements in steel matrix and oxidation environment, composition and surface morphology of formed oxides. This report will also explore how the …

Thermo-Gravimetric Analysis Of Variables Of Oxidization, Clark Nguyen, Mario F. Buchely

Undergraduate Research Conference at Missouri S&T

Oxidation phenomena play a critical role in high temperature metallurgical processing and the performance during life cycle of components made of both high and low alloy steels. Therefore, the development of a precise experimental methodology to quantify oxidation processes is critically important. This report summarizes my experimental study of the oxidation behavior of high and low alloy steel, including kinetics of surface oxide layer formation and spallation. The focus of study was in determining the complex interactions between alloying elements in steel matrix and oxidation environment, composition and surface morphology of formed oxides. This report will also explore how the …

A Guide To Fifty Years Of Research At Montana Tech: Part 3-Decontamination Of Ratioactively Contaminated Steel By Melt Refining/Slagging Processing, Larry G. Twidwell, Samuel A. Worcester

Metallurgy

This presentation includes a discussion of the research conducted at Montana Tech in the Department of Metallurgical and Materials Engineering. The discussion is focused on Decontamination of Radioactively Contaminated Steel by Melt Refining/Slagging. This presentation is based on the research of Master of Science graduate students, industrial and academic colleagues, at the Montana College of Mineral Science and Technology (which morphed to Montana Tech [1977], then to Montana Tech of The University of Montana [2000], then to Montana Technological University [2019]). The referenced work of each of the graduate students in this presentation is gratefully acknowledged. The following summary presentation …

Segregation And Heat Treatment Response Of Cast Quench And Partition Steels, Mujeeb Hussain Shaik

Masters Theses

Quench and partition (Q&P) steels have emerged as promising alternatives to traditional quenching and tempering methods, offering a superior balance of strength and ductility due to their unique microstructure of martensite, and retained austenite. This literature review examines the development and optimization of Q&P steels, focusing on their mechanical properties, heat treatment processes, and applications in various industries. This study explores the application and effectiveness of the Quench and Partition (Q&P) heat treatment process on cast steels and examines segregation phenomena in cast medium Mn steels. Medium Mn steels were employed for various Q&P cycles on cast specimens to investigate …

The Behavior Of ½⟨111⟩ Screw Dislocations In W–Mo Alloys Analyzed Through Atomistic Simulations, Lucas A. Heaton, Kevin Chu, Adib J. Samin

Faculty Publications

Analyzing plastic flow in refractory alloys is relevant to many different commercial and technological applications. In this study, screw dislocation statics and dynamics were studied for various compositions of the body-centered cubic binary alloy tungsten–molybdenum (W–Mo). The core structure did not appear to change for different alloy compositions, consistent with the literature. The pure tungsten and pure molybdenum samples had the lowest plastic flow, while the highest dislocation velocities were observed for equiatomic, W_0.5Mo_0.5 alloys. In general, dislocation velocities were found to largely align with a well-established dislocation mobility phenomenological model supporting two discrete dislocation mobility regimes, …

Inhibited Surface Diffusion In Nanoporous Multi-Principal Element Alloy Thin Films Prepared By Vacuum Thermal Dealloying, Tibra Das Gupta, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Nanoporous structures with 3D interconnected networks are traditionally made by dealloy- ing a binary precursor. Certain approaches for fabricating these materials have been applied to refrac- tory multi-principal element alloys (RMPEAs), which can be suitable candidates for high-temperature applications. In this study, nanoporous refractory multi-principal element alloys (np-RMPEAs) were fabricated from magnesium-based thin films (VMoNbTaMg) that had been prepared by magnetron sputtering. Vacuum thermal dealloying (VTD), which involves sublimation of a higher vapor pres- sure element, is a novel technique for synthesizing nanoporous refractory elements that are prone to oxidation. When VMoNbTaMg was heated under vacuum, a nanoporous structure was …

Synthesis Of Ni-Based Intermetallics By Electrolytic Plasma Processing Of Ti And Ti-Based Alloys, Chuzhong Zhang

Material Science and Engineering Dissertations - Archive

EPP is an innovative surface modification technique that enables the deposition of metal ions from the electrolyte and their integration with substrate atoms to form intermetallic compound surface layers. EPP offers advantages such as high deposition rates, environmental cleanliness, and operational simplicity. In this study, Ni-Ti intermetallic layers were successfully synthesized on a Ti-6Al-4V substrate using EPP. The properties of the resulting Ni-Ti intermetallic layers were characterized using SEM, EDS, XRD, TEM, nanoindentation, and tribology tests.

This work aims to understand the fabrication mechanism and investigate the effects of various processing parameters on the EPP process. Key factors such as …

Quantitative Modeling Of Micro Discharge And Oxide Growth In Plasma Electrolytic Oxidation Of Titanium, Kingsley I. Ochiabuto

Material Science and Engineering Dissertations - Archive

Plasma electrolytic oxidation (PEO) has been extensively applied in the past to improve the tribological properties of titanium and its alloys allowing their widespread use in industrial applications. However, the complete PEO mechanism of action remains unclear. While there are several mathematical models providing useful insights into the PEO process, they do not fully incorporate the effect of applied potential on the outcomes of PEO. In this work, we develop an experimentally informed computational model by expanding on the dielectric breakdown model. We incorporate experimental data to extract key parameters, exploring the iterative dependency of the oxide thickness and ionic …

Effects Of Additions On The Microstructure, Macrostructure, And Mechanical Properties Of Gray Iron, Evan J. Carter

College of Graduate Studies: Theses & Dissertations

The iron matrix is a major component of the gray iron (GI) microstructure, which is the transformation product of austenite during solidification. It is generally accepted that the structure of the austenite will impact the final grain structure and thus the properties of GI. Refinement of the austenite grain structure has the potential to increase the strength of GI. Knowledge of controlling austenite grain size with common alloy additions in GI is very limited and is investigated in this research. Utilizing the DAAS heat treatment process, the austenite grain boundaries can be retained and observed directly. The observations were correlated …

Solidification Cracking In Additively Manufactured High Entropy Alloy Nicrcofe With V Or W, Andrew R. Walch

Dissertations, Master's Theses and Master's Reports

Recent sustainability efforts have reduced CO2 emissions from electricity generation by increasing operating temperatures and pressures in advanced ultra-supercritical (A-USC) power plants. However, the extreme operating conditions in these A-USC power plants require new high temperature materials. The recent study of nickel-based high-entropy alloys (HEA) represents the latest approach to meet the specifications for A-USC operations. A CALculation PHase Diagram (CALPHAD) driven Bayesian optimization method was used to design the composition of alloys composed of NiCrCoFe with V or W, which were fabricated via wire-based additive manufacturing to enable high throughput development. Although the alloy was designed to minimize solidification …

Parametric Optimization Of Friction Stir Welding Of Aa6061-T6 Samples Using The Copper Donor Stir-Assisted Material Method, Aiman H. Al-Allaq, Joseph Maniscalco, Srinivasa Naik Bhukya, Zhenhua Wu, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

This study presents an optimization of the process parameters for the effect of copper (Cu) donor material percentage on the friction stir welding (FSW) of AA6061-T6 alloy. Extensive factorial experiments were conducted to determine the significance of the rotational speed (ω), the transverse speed (v), the interface coefficient of friction (μ), and the Cu donor material percentage in the plunge, left, right, and downstream zones. Design Expert 13 software was used to identify the number of simulation experiments to be conducted using the Abaqus simulation software. From Design Expert 13, which is a thorough multi-objective optimization analysis software, we were …

ผลกระทบของการอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤตต่อโครงสร้างจุลภาค และคุณสมบัติทางกลของเหล็กกล้าดูอัลเฟส, วิชยุตม์ ชูเมือง

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในการศึกษานี้ ได้มีการประยุกต์การอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤตเพื่อปรับเปลี่ยนสมบัติทางกลของเหล็กกล้าดูอัลเฟสที่มีส่วนผสม 0.107%C-2.39%Mn-0.453%Si ผลการอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤต (IC2) ถูกตรวจสอบโดยการสังเกตโครงสร้างจุลภาค การทดสอบแรงดึงและการทดสอบความแข็งแบบวิกเกอร์ แล้วจึงเปรียบเทียบผลกับชิ้นงานที่อบอ่อนระหว่างอุณหภูมิวิกฤตครั้งเดียว (IC1) โดยพบว่าการเพิ่มอุณหภูมิการอบอ่อนระหว่างอุณหภูมิวิกฤตส่งผลให้ความเค้นคราก ความต้านทานแรงดึง และความแข็งเพิ่มขึ้นในขณะที่ความเหนียวลดลงเนื่องจากการเพิ่มขึ้นของปริมาณมาร์เทนไซต์เป็นหลัก หลังจาก IC2 ส่งผลให้ชิ้นงานมีขนาดเกรนเฟร์ไรต์และปริมาณมาร์เทนไซต์ลดลงเล็กน้อย และจากผลการทดสอบแรงดึงพบว่า IC2 สามารถเพิ่มความเหนียวโดยไม่ส่งผลให้ความแข็งแรงลดลงอย่างมีนัยสำคัญ จากผลลัพธ์ที่ได้บ่งบอกว่าสามารถใช้วิธีการอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤต เพื่อปรับปรุงคุณสมบัติทางกลของเหล็กกล้าดูอัลเฟสได้ โดยไม่เพิ่มความซับซ้อนให้กับกระบวนการผลิตมากเกินไป

Processing Of Niti Sma For High Reflectivity Applications, Nicholas Dean Asbury

UNF Graduate Theses and Dissertations

Nickel Titanium (NiTi) is a shape memory alloy (SMA) that is capable of being deformed and subsequently returned to the original shape through heating. This unique property makes NiTi a prime material for potential applications in the aerospace industry. As manufacturing capabilities advance, the ability to produce and implement advanced materials, such as shape memory alloys like NiTi, becomes more feasible. One such application being studied is deployable mirrors for imaging satellites. Reflector and mirror surfaces for imaging in the visible and infra-red range of the light spectrum require low surface roughness across the largest allowable area for the collection …