Materials Science and Engineering Commons^™

Effect Of Microstructural Features On Steel Machinability, Mark C. Emmendorfer

Masters Theses

Non-metallic inclusions can have a tremendous impact on the machinability of steel. Some oxide inclusions such as alumina, spinel, and other refractory abrasive oxide inclusions can have a detrimental effect on machinability. Modification of oxide inclusions by calcium treatment can promote the formation of low melting point oxides such as anorthite and gehlenite inclusions that can assist in chip formation and form a lubricating layer on the rake surface of the machine tool. MnS is known to be beneficial to improving the machinability of steel. They assist in chip formation by being heavily deformed in the primary shear zone. Sulfide …

Characterization And Tailoring Of Powder Used In Additive Manufacturing And Plasma Spheroidization, Caitlin S. Kriewall

Masters Theses

"There are many processes that use metal powder as the starting material for the production of parts. With the growth of these manufacturing techniques, more critical part applications are being considered. In order to fully understand the process and create consistent parts, powder properties need to be well understood. Selective laser melting (SLM) is a powder bed-based additive manufacturing process. During processing, heat-affected powders are generated and can deposit within the build area. The current work investigated the characterization of heat-affected 304L stainless steel powder using techniques such as scanning electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy to detect …

Microstructural Development And Its Effect On Aqueous Corrosion Of A Borosilicate Glass Ceramic For Waste Vitrification, Nicholas Stephen Roberts

Masters Theses

"Waste loadings of reprocessed spent nuclear fuel vitrified into borosilicate glass can be increased by precipitating environmentally stable phases concentrated with waste components in a chemically stable glass matrix. The principal objective of this thesis was to characterize the development of crystalline powellite (CaMoO₄ and related phases) and oxyapatite (Ca₂LN₈Si₆O₂₆) in borosilicate glass-ceramics and to determine how the formation of those phases affected its chemical durability.

Borosilicate glasses provided by PNNL were re-melted and quenched at rates from over 300⁰C/s to ~0.05⁰C/s. Isothermal heat treatment experiments were conducted by quenching melts …

Corrosion Performance Of Zirconium-Based Passivations On Electroplated Zinc Nickel, Madison Morgan Reed

Masters Theses

“Performance requirements for Department of Defense (DoD) electrical components include corrosion and electrical contact resistance. Historically, electroplated cadmium with a chromate conversion coating (CrCC) has been used to meet corrosion and contact resistance standards. However, replacements are needed for these materials because they are toxic and carcinogenic. Electroplated γ-ZnNi has been identified as an acceptable alternative to Cd. This study evaluated commercially available Zr-based thin films and sealers as passivations for potential replacement of CrCCs. Ten different passivations were tested and compared with bare γ-ZnNi. X-Bond and Zircobond passivations were found to provide some improvement to the bare ZnNi corrosion …

The Modification Of A Curtain Coating Formulation: A Study Of Rheology And Surface Tension, And Their Effect On Pitting, Samantha Leigh Schoenfelder

Masters Theses

When an undisclosed recycled fiber mill installed a “two-slotted” curtain coater to replace their air knife coater, a prominent defect arose known as “pitting,” which is also called pinholing or cratering. Pitting occurs when the coating of the sheet has small holes that mar its surface, which, when clustered together or larger in size, can cause print breakup during the printing process.

Through research, pitting is known to be caused by a boundary layer of air that gets laterally pulled in between the coating and board during their initial contact. Thus, rheological properties and the surface tension of the curtain …

Development Of An Effective Portable And Flexible Glove For Hand Tremor Suppression, Abdulrahem Turkistani

Masters Theses

This paper presents the work carried out in designing and developing a prototype for a tremor suppression system that reduces hand tremor by counteracting vibrations initiated from a patient’s shaking hand. This system includes a glove with a built-in vibration simulation module that oscillates and mimics the hand vibration. The oscillation is generated by a DC motor mounted on the top of the glove, and can vary in degree of vibration. The glove is also equipped with an accelerometer-gyroscope based micro-electromechanical system (MEMS) and vibrating coin motors mounted on each finger, both interfaced with a microcontroller. The microcontroller used in …

In-Situ Control Of Substrate Temperature In Additive Manufacturing To Homogenize Micro-Hardness Of Laser Clad Deposits Using Thermo-Electric Cooling, Raghu Ram Kolla

Masters Theses

”Nickel hard-surfacing alloys are replacing hard Chromium coatings due to their excellent wear and corrosion-resistant properties. In laser cladding of these alloys, however, these properties can vary across the height of the deposit due to an accumulation of excess heat generated in the deposit during the process. This may result in uneven wear of the clad parts which can be detrimental for practical purposes. The research objective is to develop an in-situ cooling system that works in line with the laser deposition system to extract the excess heat buildup and reduce the variation in the hardness of the Ni-based clad …

Cathodic Protection Measurement Through Inline Inspection Technology Uses And Observations, Briana Ley Ferguson

Masters Theses

"This research supports the evaluation of an impressed current cathodic protection (CP) system of a buried coated steel pipeline through alternative technology and methods, via an inline inspection device (ILI, CP ILI tool, or tool), in order to prevent and mitigate external corrosion. This thesis investigates the ability to measure the current density of a pipeline's CP system from inside of a pipeline rather than manually from outside, and then convert that CP ILI tool reading into a pipe-to-soil potential as required by regulations and standards. This was demonstrated through a mathematical model that utilizes applications of Ohm's Law, circuit …

Mold Flux Crystallization And Mold Thermal Behavior, Elizabeth Irene Peterson

Masters Theses

"Mold flux plays a small but critical role in the continuous casting of steel. The carbon-coated powder is added at the top of the water-cooled copper mold, over time it melts and infiltrates the gap between the copper mold and the solidifying steel strand. Mold powders serve five primary functions: (1) chemical insulation, (2) thermal insulation, (3)lubrication between the steel strand and mold, (4) absorption of inclusions, and (5)promotion of even heat flux. All five functions are critical to slab casting, but surface defect prevention is primarily controlled through even heat flux. Glassy fluxes have high heat transfer and result …

Processing And Properties Of Wc-Based Cu-Ni-Mn-Zn Metal Matrix Composites Produced Via Pressureless Infiltration, Paul M. Brune

Masters Theses

"This research focuses on the processing and properties of tungsten carbide-based (WC-based) Cu-Ni-Mn-Zn metal matrix composites (MMCs) fabricated by pressureless infiltration. The first goal of this project was to test the wettability of Cu-Ni-Mn and Cu-Ni-Mn-Zn on various carbides. The sessile drop technique was employed to determine if they were suitable candidates for pressureless infiltration. The carbides investigated were TaC, WC, B₄C, and SiC. It was determined that both alloys had contact angles of less than 70⁰ on TaC, WC, and B4C, which is one requirement for pressureless infiltration. However, both alloys reacted with B₄C to …

Evaluation Of Non-Chromate Passivations On Electroplated Γ-Phase Zinc Nickel, Steven Michael Volz

Masters Theses

"This research focused on the corrosion response and electrochemical behavior of electroplated low hydrogen embrittlement alkaline γ-phase zinc nickel with passivation layers. The motivation was the need to replace hexavalent chromium conversion coatings in military grade electrical systems with a more environment friendly alternative. The passivation layers were employed for the purpose of mitigating corrosion attack while maintaining low contact resistance. Trivalent chromium-based passivations and cerium-based passivations were compared against the currently used hexavalent chromium conversion coating. The coating systems were compared using electrochemical impedance spectroscopy, cyclic potentiodymanic scans, salt spray exposure testing, electrical resistance measurements, microstructure analysis, and compositional …

Processing, Microstructure, And Properties Of Engineered Diboride Structures, Connor Charles Wittmaier

Masters Theses

"The mechanical properties and processing parameters of boride ceramics in foam and laminate architectures were evaluated. The ceramic reticulated foam was produced through a polymer substrate replication technique and the hardness and compressive strength were tested. The laminate structure was tested to evaluate the flexure strength and work of fracture as a function of temperature.

The foam architecture was produced using a TiB₂ slurry coating on a polyurethane reticulated foam preform. Foams sintered to 2150⁰C displayed an average grain size of 8.9 ± 7.3 µm, and a hardness of 17.3 ± 2.4 GPa. Crush testing foams were sintered at …

Overview Of Co₂ Leakage Problems And Sealants For Co₂ Leakage Remediation, Shudai Peng

Masters Theses

"Excessive Carbon Dioxide (CO₂) emission has become a serious issue and caused lots of environmental problems. Carbon Capture and Storage (CCS) program has been developed to reduce the CO₂ content in the atmosphere. CO₂ storage has been targeted mainly on depleted oil or gas reservoirs and deep saline aquifers. However, leakage could occur through wellbores, cap rocks, formation faults, and fractures during and after CO₂ injection. To minimize the risk, different types of sealants have been investigated to prevent CO₂ leaks. The aim of this thesis is to provide a comprehensive review of the materials which could be used as …

An Investigation Of Borax For Sealing Inflow From Berea Sandstone, Tri-Tris Bao Nguyen

Masters Theses

"Well inflow control is a major challenge for the oil and gas industry. Erle Haliburton revolutionized well inflow control with his patent for cementing oil wells in 1921. Soon after, cement became the accepted material to establish well integrity and has been ever since. Cement is used in all phases of the well life cycle, and it is expected to hold indefinitely once set. Yet based on the nature of cement and the placement techniques, flow pathways may develop from improper cementing jobs or from cement degradation over time. Well integrity is especially crucial for wellbore plugging and abandonment, since …

Minimization Of Metamerism In Wood Grain Printing Using Different Gcr Settings, Vinay Anil Turke

Masters Theses

In printing industry, prototyping is necessary to ensure quality reproduction of jobs. Conventional printing processes like gravure cannot be used for prototyping because of high manufacturing cost of gravure cylinders. Such challenges can be successfully tackled by use of relatively cheap and flexible printing processes, such as inkjet. Even though inkjet printing is a cost effective way for prototyping, it has its own limitations, especially in the case of woodgrain printing. Wood-grain patterns need to be printed with a release coating and adhesive. Inkjet printers are incapable of printing release coating and adhesive because release coat and adhesive require certain …

Phase Field Modeling Of Electrodeposition Process In Lithium Metal Batteries, Nihal Acharya

Masters Theses

"One of the main weaknesses in long term performance of conventional lithium batteries is the growth of lithium microstructures on the electrode surface due to an electrochemical process, which can eventually lead to failure of these batteries. Suppressing this microstructure growth is a key in developing new generations of lithium metal batteries (LMBs). In this study, a two-dimensional (2D) phase field model is constructed to understand and determine the parameters controlling formation and evolution of microstructures in LMBs. A Ginzburg-Landau free energy functional, which is a function of concentration of Li⁺ and applied voltage, and a system consisting of …

Material Properties Affecting The Penetration Of Metal Targets By Copper Linear Shaped Charges, Kevin Lee Phelps

Masters Theses

"A linear shaped charge (LSC) is an explosive device used in demolition, aerospace, and in other applications that require the cutting of metal. Users of LSC's typically know the size of shaped charge needed to cut their target but commonly encounter previously untested materials. The motivation for this thesis is to provide an understanding as to what target material properties are good indicators of cutting performance so the selection of LSC can be more efficient. The author found that penetration theories for other types shaped charges were insufficient for the LSC, possibly because of the relatively slow projectile created by …

Thermal Characterization Of Phase Change Materials For Thermal Energy Storage, Rami Mohammad Reda Saeed

Masters Theses

"The study provides a valuable and useful database for Phase Change Materials (PCMs) for Thermal Energy Storage (TES) applications. Only a few existing studies have provided an overall investigation of thermophysical properties of PCMs in this detailed manner. Several organic PCMs, namely Myristic acid, Capric Acid, Lauryl Alcohol, Palmitic acid and Lauric acid, have been characterized after being carefully selected to cover wide range of TES applications. Insights and information gained from this work will be applied toward the design and modelling of many low temperature thermal energy storage applications. The study experimentally investigated uncertainty of thermal characterization of PCMs …

Carbon Transfer From Magnesia-Graphite Ladle Refractories To Ultra-Low Carbon Steel, Andrew Arthur Russo

Masters Theses

"Ultra-low carbon steels are utilized in processes which require maximum ductility. Increases in interstitial carbon lower the ductility of steel; therefore, it is important to examine possible sources of carbon. The refractory ladle lining is one such source. Ladle refractories often contain graphite for its desirable thermal shock and slag corrosion resistance. This graphite is a possible source of carbon increase in ultra-low carbon steels. The goal of this research is to understand and evaluate the mechanisms by which carbon transfers to ultra-low carbon steel from magnesia-graphite ladle refractory.

Laboratory dip tests were performed in a vacuum induction furnace under …

A Study On Non-Metallic Inclusions In Foundry Steel Process, Marc Leonard Harris

Masters Theses

"The effects of sample area and automated SEM/EDS feature analysis parameters (step size, magnification and threshold) on nonmetallic inclusion characterization results has been investigated and optimized. A post-processing program was developed to automatically determine average inclusion chemistry, total element concentrations within inclusions, and for generating joint ternary diagrams with size visualization for representing nonmetallic inclusion populations. Using these tools the evolution of nonmetallic inclusions was examined for 4320 steel at a participating industrial steel foundry. The steel was sampled throughout electric arc furnace melting through ladle refining to the final casting where an in-mold sampling procedure was developed to procure …

Hybrid Manufacturing Processes For Fusion Welding And Friction Stir Welding Of Aerospace Grade Aluminum Alloys, Megan Alexandra Gegesky

Masters Theses

"Friction stir welding and processing can provide for joints in aerospace grade aluminum alloys that have preferable material properties as compared to fusion welding techniques. Aerospace grade aluminum alloys such as AA2024-T3 and AA7075-T6 are considered non-weldable by traditional fusion welding techniques. Improved mechanical properties over previously used techniques are usually preferable for aerospace applications. Therefore, by combining traditional fusion welding and friction stir processing techniques, it could be plausible to create more difficult geometries in manufactured parts instead of using traditional techniques. While this combination of fusion welding and friction stir processing is not a new technology, its introduction …

Synthesis Of Radioactive Nanostructures In A Research Nuclear Reactor, Maria Camila Garcia Toro

Masters Theses

In this work, the synthesis of radioactive nanostructures by water radiolysis was studied. The irradiation processes were done in the Missouri University of Science and Technology research nuclear reactor (MSTR).

Radioactive gold nanoparticles (AuNPs) were synthesized from aqueous solutions containing the metal salt precursors by radiolysis of water. Seven different samples were irradiated at 200kW of thermal power for 0.5, 1, 3, 5, 10, 30, and 60 minutes. The average sizes of the obtained nanoparticles ranged from 3 nm to 400 nm, it was found that the particle size decreased with the irradiation time. Some agglomerations of particles were found …

Synthesis And Photonic Sintering Of Bioresorbable Zinc Nanoparticle Ink For Transient Electronics Manufacturing, Bikram K. Mahajan

Masters Theses

"Zinc is an essential 'trace element' that supports immune systems, and is required for DNA synthesis, cell division, and protein synthesis. Zinc nanoparticles (Zn NP) has antibacterial properties and potential to be used in biodegradable printed electronics devices. The research presented here is about the synthesis of Zn NP and their potential use in transient electronics devices. In Paper 1, a technique of room temperature synthesis of Zn NP is reported using ball milling. Controlled amount of PVP was mixed in the solvent to stabilize the Zn particles and minimize cold welding during milling. The size of the produced Zn …

Biodegradable Electronic And Optical Devices Toward Temporary Implants, Md Shihab Adnan

Masters Theses

"Implantable biomedical devices have a high potential to revolutionize health care technologies in near future. Implantable devices can be classified as permanent prosthetic devices such as pacemakers or nerve stimulants and temporary devices for intermediate monitoring and control scenario which are still in research phase. In contrast to permanent device, temporary implants lose functionality and become unnecessary after intended operational lifetime which may pose serious electromagnetic and biomedical safety concern, latent complications at the implanted sites and possible ethical issues if not removed from body by an additional surgical operation.

The first paper of this thesis focuses on exploring the …

Computational Fluid Dynamics (Cfd) Simulations Of Molten Steel Flow Patterns And Particle-Wall Adhesion In Continuous Casting Of Steels, Mahdi Mohammadi-Ghaleni

Masters Theses

"In this research, the measurements of clog deposit thickness on the interior surfaces of a continuous casting nozzle were compared with Computational Fluid Dynamics (CFD) predictions of melt flow patterns and particle-wall interactions to identify the mechanisms of nozzle clogging. A hybrid turbulent approach, Detached Eddy Simulation (DES), was configured to simulate both turbulent structures and particle-wall interactions inside the nozzle accurately. For experimental measurements of nozzle clogging, a nozzle received from industry was encased in epoxy and carefully sectioned to allow measurement of the deposit thickness on the internal surfaces of the nozzle. CFD simulations of melt flow patterns …

Oxidized Phospholipids Regulation Of The Monocyte Recruitment Parthway In Human Aortic Endothelial Cells, Piao Jian Tan

Masters Theses

Low-density lipoprotein particles in blood plasma invade the endothelium and become oxidized, creating risk of CHD associated with atherosclerosis, the main underlying condition in coronary heart disease. Oxidation products of the phospholipid 1-palmitoyl- 2-arachidonoyl-sn-glycerol-3-phosphatidylcholine (PAPC) are bioactive components of minimally oxidized LDL that stimulate endothelial cells that line the artery, leading to monocyte binding and atherosclerosis. It is hypothesized that the regulation of the monocyte recruitment pathway by these oxidized phospholipids is mediated by the binding of OxPAPC to one or more mediating proteins. Human recombinant VEGFR2, GRP78, and EP2bind to OxPNB, a biotinylated analog of OxPAPC, demonstrated using Western …

Zinc Oxide Based Inks For Semiconductor Applications, Shreyas Pathak

Masters Theses

Conventional printing methods are gaining popularity in the manufacturing of electronic components hence being termed as Printed Electronics (PE). IDTechEx has predicted that the total market size of flexible electronics by 2024 would be $70.4 billion. Their report predicts that majority of applications would consume conductive inks. (1)

The main challenge in PE is developing suitable inks for the different printing processes being used to manufacture these electronic components. The experiments in this work mainly involved selecting suitable components for formulating solvent based, semiconductive ZnO inks and then sintering using the NovaCentrix® PulseForge® 1200. ZnO inks were also doped with …

Healing Of Bone Defects In A Rodent Calvarial Defect Model Using Strong Porous Bioactive Glass (13-93) Scaffolds, Yinan Lin

Masters Theses

"The main objective of this project was to evaluate the capacity of strong porous silicate (13-93) bioactive glass scaffolds prepared by a robocasting technique to regenerate bone and stimulate angiogenesis in a rat calvarial defect model. The scaffolds were created with the same grid-like microstructure but in a variety of formulations: (i) as-fabricated, (ii) pretreated in an aqueous phosphate solution to convert the glass surface to hydroxyapatite, (iii) loaded with bone morphogenetic protein-2 (BMP2) (1 µg per scaffold), and (iv) doped with copper (0.4-2.0 wt. % CuO). When compared to the as-fabricated scaffolds, the pretreated scaffolds enhanced bone regeneration at …

Hybrid Manufacturing Process Of SicF/Sic Composite Using Preceramic Polymer, Robert Raymond Meinders

Masters Theses

"Continuous fiber-reinforced silicon carbide (SiC_f/SiC) ceramic composites have been increasingly used due to their high temperature strength and graceful failure mechanisms. A disadvantage is the high cost and lengthy production processes that are required to develop these materials. Polymer infiltration and pyrolysis (PIP) is one of the most attractive fabrication processes for composites due to shape flexibility, mass production and relatively low cost; however, the quality of material obtained by this method has been considered insufficient due to the microstructure defects of the material obtained. This study investigated a hybrid of multiple polymer manufacturing processes to maximize quality …

Factors Affecting The Heat Transfer During The Dip Testing Of Potential Third Generation Advanced High Strength Steels, Kramer Michael Pursell

Masters Theses

"A dip tester was designed and built at Missouri University of Science and Technology to test the effects of the primary alloying elements (Mn, Si, and Al) of Fe-Mn-Al-Si-C type 3rd generation advanced high strength steel (AHSS) alloys, dipping superheat, and dipping speed on the heat transfer during rapid solidification. The difficulties associated with casting 3rd generation AHSS were compiled as well to serve as a best-practices guide. An extensive list of potential 3rd generation AHSS alloys was developed and tested, and the effects of various dip testing parameters were examined.

Manganese was found to increase the heat flux by …