Materials Science and Engineering Commons^™

Viability Of A Proposed Transparent Fluid Model For Analog Metal Casting Filling Process, Andres Segura Irazoqui

Dissertations and Theses @ UNI

This research work was conducted to develop a proposed transparent fluid model to mimic dross formation and dispersion in metal castings during the mold filling process. The major cause for dross formation includes the air entrainment, surface turbulence, and bubbles, which create oxide films inside the molten metal. The oxide films are trapped inside the casting after solidification causing detrimental effects on the mechanical properties of the casting.

The objective of the investigation was to explore the feasibility using phenolic urethane as a transparent fluid material to investigate air entrainment mechanism. The experimentation consists of the following materials: the phenolic …

Influence Of Sonication Parameters On The Morphology Of Nanocellulose Aerogels, Dexter Cox, Tim Kidd

Research in the Capitol

Nanocellulose is a renewable and biocompatible material that has a tensile strength similar to aluminum, is stiffer than Kevlar, and has a strength to weight ratio eight times that of stainless steel. There has been a range of studies on nanocellulose materials for potential use as a low-calorie food substitute, biomedical wound dressings, and as a structural component for buildings. Throughout this research experiment, nanocellulose aerogels of different mass compositions were created through a mechanical process using an ultrasonic processor with a titanium probe attachment. The purpose of this study was to develop a method that reduces the amount titanium …

An Investigation Into The Prediction Of Double-Skin Penetration Within Chromite Molds And Cores In Heavy Section Steel Casting Using Process Simulation Software, Nathaniel Bryant

Dissertations and Theses @ UNI

This investigation was conducted in response to a commercial steel foundry approaching the University of Northern Iowa for assistance with a recurring defect they experienced on a production casting. The defect was described as a mass of metal that penetrated and consumed the interstices of their chromite molds and cores, and it was determined to consist of fayalite. After an extensive literature review, it was concluded that the foundry experienced the double-skin defect, a niche quality issue that most commonly occurs in heavy-section steel casting with chromite molding materials

After it was determined that the double-skin defect was occurring, a …

Effect Of Fe Substitution On Structural, Magnetic And Electron-Transport Properties Of Half-Metallic Co2tisi, Juliana Herran, Parashu Kharel, Pavel Lukashev

Research in the Capitol

In recent years, research on magnetic materials has been one of the most technologically appealing developments in materials science. Among other applications, magnetic materials are essential components of data storage and information processing in computer hardware elements, such as hard drives and random access memories. Here, we present a theoretical study of structural, magnetic and electronic properties of ferrimagnetic Co₂Ti_1−xFe_xSi (x = 0, 0.25, 0.5), using density functional calculations. We show that the magnetic moment of Co₂Ti_1−xFe_xSi increases when Ti is substituted with Fe, consistent with experimental findings. …

Analysis Of Vibrational Modes Of Chemically Modified Tone Wood, Madison Flesch

Honors Program Theses

It is generally accepted that every violin has different tone quality in terms of intonation and the depth of the harmonics produced. The best violins are made by experienced luthiers that craft each with precision to produce the best possible tonal quality. The quality of the finished violin is dependent upon both the specific shape and the vibrational response of the wood used in its construction. Because the hard wood used in violin construction is inhomogeneous, the composition and structure of material used is critical to the final product.¹ Luthiers would initially rely on their experience to feel the …

Sand Distribution Effect On Three Dimensional Printed Sand Properties, Kip Woods

Dissertations and Theses @ UNI

The purpose of this study was to assess the performance characteristics of commercially available round grain silica sand for the use in three-dimensional sand printers. Two different average diameters were selected to examine the effects of screen distribution on printing performance; these diameters were 57-grain fineness number (GFN) and 70 GFN. These sands were a high purity round grain silica and had low trace contaminates, to reduce any possible influence from contaminates.

The resin system utilized in this investigation was a commercially available Furan resin system. Two test specimens were used in this study the American Foundry Society (AFS) tensile …

An Experimental Study Of Non-Metallic Inclusions Precipitation And Its Effect On Impact Toughness Variations In Low Alloy Steel Subjected To Complex Deoxidation, Pavel Bizyukov

Dissertations and Theses @ UNI

A low level of non-metallic inclusions in steel is the key requirement in the concept of clean steel. Although the concept has received its name quite recently, it has been implemented at the large-scale steel mills for more than 40 years. Production of clean steel became possible due active development and adoption of the post-melting treatment of molten metal in the teeming ladle. Ladle metallurgy, an umbrella term for various methods of treatment, includes operations that cannot be performed during primary metallurgical processes such as melting in an electric arc, basic oxygen, or air induction furnace. Initially, the most common …

Magnetic Behavior Of Bulk And Nanostructured Mnxtas2, Lucas Paul Beving

Honors Program Theses

At its base, material science research aims to categorize specific materials by their various attributes, such as structure, integrity, electronic properties, magnetic properties, and others. By categorizing materials in this way, it becomes easier to generalize the application of a specific material to those within a broader category. The interest in materials that exhibit useful characteristics at small scales derives directly from the technology industry’s need for smaller and smaller devices. Two-dimensional materials are of great interest for this reason.

Two-dimensional materials are comprised of many single layers, or planes, stacked together to create a crystal. Each layer may be …

Spin-Gapless Semiconductivity And Half Metallicity In Heusler Alloys, Bradley A. Staten, Pavel V. Lukashev

Research in the Capitol

In recent years, ever increasing interest in spin-based electronics (spintronics) has resulted in the search for a new class of materials that can provide a high degree of transport spin polarization. An ideal candidate would act like insulator for one spin channel and a conductor or semiconductor for the opposite spin channel (e.g. half metals (HM), spin gapless semiconductors (SGS)). In this work, we present results of our computational and theoretical study (Staten, et al., J. Appl. Phys. 117, 17D115 (2015)) of Heusler compounds with potential commercial applications in the field of spintronics. We show that naturally these materials are …

Corn Stover Biochar In Gypsum Board: Empirical Analysis Of Thermal Conductivity And Flexural Strength, Albena Yordanova

Dissertations and Theses @ UNI

Gypsum board, an economical and durable finish material for wall and ceiling construction in the United States and worldwide, is the component with the lowest thermal performance in a typical exterior wall assembly. It also constitutes a substantial portion of construction waste in landfills, potentially creating harmful environmental effects and dangerous gases. To minimize the negative effects of fast growing construction waste of gypsum in landfills and meet higher standards for energy efficiency in construction, there is a need to explore sustainable ways of improving thermal properties of gypsum board and recycling the material. Gypsum can be recycled and used …

Process And Apparatus For Manufacturing Grease, Lou A. T. Honary, James E. Wesley

Patents (University of Northern Iowa)

A process and corresponding apparatus and system for use in preparing soaps from fatty acid containing oil compositions, and in turn, for preparing greases by the use of such soaps in combination with one or more base oils.

Preliminary Investigation Into The Cause Of Pinhole Porosity In Aluminum Metal Castings From Serpentine Impurities In Olivine Sand, Brodie J. Biersner

Dissertations and Theses @ UNI

The problem addressed in this study is how contaminates in the foundry molding aggregate olivine, affect aluminum castings during the casting process. This research will concentrate on hydrated contaminates, specifically the mineral serpentine. The purpose of this research is to better understand how hydrated minerals contribute to the generation of pinhole porosity defects during the casting process. Understanding how impurities in foundry aggregates affect the casting process would aid in the reduction of scrap caused by core and molding sands, ultimately providing savings to the casting manufacturer.

A foundry grade olivine was compared to a new source of olivine to …

Humic Substances-Based Polymer System, Gerard R. Thiel

Patents (University of Northern Iowa)

A system for use in forming polymer compositions, including as a replacement for phenolic based resin systems, for instance, in preparing foundry molds. In a preferred embodiment, the system includes the use of a) a polyermizable hydroxyl-containing component comprising a humic substance (as can be provided by lignite), b) an isocyanate component, and c) a catalyst, and preferably amine catalyst, component adapted to catalyze the polymerization of a) and b). The system is optionally used as binder system in the presence of a filler, such as, in combination with a foundry aggregate such as sand. A polymer system of this …

The Environmental Performance Of Biobased Resin Within Phenolic-Urethane Nobake Binders: A Feasibility Study, Ian David Morgan Williams

Dissertations and Theses @ UNI

The objectives of this research were to investigate the discovery and development of a biobased nobake binder resin for use within the foundry industry toward improved energy efficiency and environmental performance. The performance of polysaccharides within biobased resins was evaluated using industry-accepted methods and standards such as cure rate, tensile-strength development, and casting performance based upon step cone core results. Biobased nobake resins comprised of polysaccharide raw materials cure at a rate that is comparable to conventional nobake sand binders. Upon reaching stripping time, the development of biobased resin reveals a rapid increase in tensile strength, reaching 80% of its …

Growth And Characterization Of Nanoscale Thin Films, Erik Thomas Wolter

Honors Program Theses

Thin manganese films were grown by thermal evaporation in high vacuum. The growth rate was varied to determine how the growth rate affects the continuity of ultra-thin films. The resistance was measured with the two-point method in situ and the data was recorded digitally. The resistance was converted to resistivity and this was plotted against thickness. It was found that resistivity decreases exponentially as the film begins to form in islands. The film reaches a critical thickness as the islands coalesce and the data can then be fitted with Fuchs’ equation. The resistivity continues to decrease but the minimum resistivity …

Virtual Coatings Application System, Jason M. Ebsensberger, Michael J. Bolick, Richard J. Klein Ii, Eric C. Peterson, Chad J. Zalkin, James B. Fisher, Leslie C. Hughes

Patents (University of Northern Iowa)

A virtual coatings application system has several features to enhance the realism of simulated spray painting. The system generally includes a display screen on which is defined a virtual surface (such as a truck door) that is intended to be virtually painted or coated by the user. Alternatively, the system includes a head-mounted display unit that displays a virtual spray painting environment in which the virtual surface is defined. The user operates an instrumented spray gun controller that outputs one or more signals representing data as to the status of the controls on the spray gun controller. The system also …

Virtual Coatings Application System, Jason M. Ebensberger, Michael J. Bolick, Jeremiah G. Treloar, Richard J. Klein Ii, Eric C. Peterson, Chad J. Zalkin, James B. Fisher, Leslie C. Hughes

Patents (University of Northern Iowa)

A virtual coatings application system has several features to enhance the realism of simulated spray painting. The system generally includes a display screen on which is defined a virtual surface (such as a truck door) that is intended to be virtually painted or coated by the user. The user operates an instrumented spray gun controller that outputs one or more signals representing data as to the status of the controls on the spray gun controller. The system also has a motion tracking system that tracks the position and orientation of the spray gun controller with respect to the virtual surface …

Virtual Blasting System For Removal Of Coating And/Or Rust From A Virtual Surface, Michael Bolick, Chris Lampe, Jason Ebensberger, Jeremiah Treloar, Rick Klein, Eric Conrad Peterson, Chad Jason Zalkin

Patents (University of Northern Iowa)

A computer simulation and virtual reality system simulates the use of a blasting nozzle to remove one or more coatings and/or rust from a virtual surface. The user operates an electronic controller in the form of a blasting nozzle that outputs a signal indicating whether the blasting nozzle controller is in an "on" position or in an "off" position. The system also has a motion tracking system that tracks the position and orientation of the blasting nozzle controller with respect to the virtual surface defined on the display screen. Simulation software in a computer generates virtual blast pattern data, and …

Synthesis And Characterization Of A [Ru(Bpy)2(Ncs)2] Derivative For Use As A Dye-Sensitizer In Nanocrystalline Solar Cells, Joel Thomas Kirner

Honors Program Theses

After extensive review of the field of dye-sensitized solar cells, the molecule [Ru(4,4’- dicarboxy-2,2’-bipyridine)(4,4’-di-(2-(2-pyridyl)ethenyl)-2,2’-bipyridine)(NCS)2] has been designed as an original contribution to the field. This dye sensitizer was chosen by derivatizing upon the structure of the standard sensitizer, cis-diisothiocyanatobis(4,4’-dicarboxylic acid-2,2’- bipyridine)ruthenium(II) (N3), by extending the conjugation of one bipyridine ligand. This structural derivatization should enhance light harvesting by red-shifting the dye’s absorbance and increasing the dye’s molar absorptivity, which should result in a dye-sensitized solar cell with higher efficiency. The Density Functional Theory (DFT) molecular orbital calculations of the new dye complex indicate that the HOMO is highly localized …

Preliminary Investigation Of Metallurgical Structure And Mechanical Properties Of Cast Iron With High Aluminum Content, Pavel Bizyukov

Dissertations and Theses @ UNI

The problem addressed in this study analyzed various properties of cast iron with high aluminum content. This grade of cast iron was projected for use in the automotive industry. The benefits provided with high aluminum content are lower specific gravity and relatively inexpensive source materials with the potential of achieving high temperature properties.

The purpose of the study was to select suitable source materials and determine an effective melting technique, to investigate metallurgical structure and mechanical properties at given chemical composition, and, finally, to provide elaborate results.

The design of the experiment included the following steps: (a) selection and preparation …

The Effects Of Nanoscale Disorder On The Paramagnetic To Ferromagnetic Transition In Melt-Spun Gadolinium And Gadolinium Iron Alloys, Justin Gary Bohnet

Honors Program Theses

As nanoscale science continues to flourish, scientists strive to understand how structure and order (or disorder) on the nanoscale contribute to macroscopic properties, such as magnetism. This study examines alloys of gadolinium and iron that have been nanostructured through the process of melt-spinning. The result was a two-part system consisting of small (~70 nm) gadolinium grains surrounded by an amorphous gadolinium and iron matrix. Measurements of the samples’ DC magnetization and AC susceptibility were performed. By looking at the paramagnetic to ferromagnetic transition in the materials, the critical exponents were obtained and used to classify and understand how the addition …

Light Beam Targeting And Positioning System For A Paint Or Coating Removal Blasting System, Richard J. Klein Ii, Christopher A. Lampe

Patents (University of Northern Iowa)

A blasting system for the removal of coatings or paint from an underlying surface uses an optical device to position the blasting nozzle an appropriate stand-off distance from the surface. The blasting media can use a variety of blasting media including abrasives, water, and various specialty blasting media. The preferred optical system is mounted to or integral with the blasting nozzle, and uses a diode laser, a beam splitter and a reflecting mirror to generate a reference beam and a gauge beam. Alternatively, two diode lasers can be used to generate the reference beam and gauge beam respectively. The reference …

An Investigation Into Microwave Energy To Soften Scrap Tire Rubber Aiding Existing Mechanical Separation Processes, Russell Jon Lucas

Dissertations and Theses @ UNI

This research was performed to soften scrap tires to aid in their transformation from whole tires to valuable streams of rubber and steel for reuse in industry. Actual shredded scrap rubber was used in this experiment to determine if this highly variable material could yield consistent results if subjected to volumetric heating from a magnetron emitting microwave energy.

A consumer microwave oven was used to heat this material. This oven had its control circuitry modified by using a programmable logic controller to operate the energy exposure time. The sample's surface temperature was measured utilizing a non contact infrared thermometer. All …

Modeling And Simulation To Investigate Effects Of Static Mixer, Carrier Gas, Temperature And Pressure On The Mixing Ratio Of Carbon Nanotubes Growth Reactors, David Addie Noye

Dissertations and Theses @ UNI

The problem of this study was to investigate the effects of static mixer, carrier gas, carrier gas inlet pressures, and reactor operating temperatures on the mixing ratio of carbon nanotube synthesizing reactor. The methodology included design of static mixers, mathematical modeling, and computer modeling and simulation experiments.

The simulation experiment was performed based on single phase carrier gas modeling due to difficulty and time for three phase fluid modeling. First only nitrogen carrier gas in addition to the other three factors under constant inlet flow velocity and inlet temperature was simulated. Secondly, the same procedure was applied to argon carrier …

Apparatus And Method For Measurement Of Fluid Viscosity, Feredoon Behroozi

Patents (University of Northern Iowa)

A non-contact apparatus and method for mapping the wave profile of capillary waves on a fluid surface to determine viscosity of the fluid. Two conducting blades coupled to a sine wave generator are positioned spaced laterally above and near the surface of the fluid to generate a standing capillary wave on the fluid surface between the blades. A laterally moveable fiber optic probe is coupled to a laser to transmit laser light toward the fluid surface and to receive reflected light from the fluid surface. Part of the laser light reflects from the end of the probe and creates an …

An Investigation Of Eddy Current Analysis For Laser Surface Treatment Of Steel, Ronald Edward O'Meara

Dissertations and Theses @ UNI

The problem of this exploratory study was to determine the strength of the bivariate correlational relationship between microhardness readings converted to Rockwell values and eddy current values of laser heat-treated AISI 1045 steel. Further, the microstructure was analyzed to determine the microstructural changes formed by laser surface treatment utilizing a carbon dioxide laser.

The purpose of this study was to investigate the microhardness and depth of hardness formed by laser surface treatment, to develop a measure of correlation between microhardness and eddy current values, and to study microstructural changes formed by the laser surface treatment. This knowledge could be used …

Pre-Inoculation Effect Of Sic In Production Of Thin Wall Ductile Iron Castings, Nikolay Y. Laukhin

Dissertations and Theses @ UNI

Pre-inoculation effect of SiC additions and its effect on castability, microstructure, and magnesium recovery in thin wall ductile iron plates have been studied. Experimental results were compared with alternative FeSi75 furnace pre-inoculation additions.

The first series of experiments aimed to set the baseline of iron quality, when using FeSi75 pre-inoculant

In the second series of experiment, different methods of introduction of Sic into liquid iron were studied. It was established that Sic added into the stream during the tapping into the flow-through chamber or added directly into the flow-through chamber produced lower Si recovery. The most effective method of introduction …

An Evaluation Of The Ductile Iron Casting Training Program At The Industrial Technology Department Of A Midwestern University, Khalid D. Alkarimy

Dissertations and Theses @ UNI

The purpose of this study is to determine how efficient this training program is as measured by (a) increasing the knowledge of new employees about the ductile iron casting process and other casting processes as perceived by the participants, (b) participants achievement of the program learning objectives as perceived by the participants, and (c) a positive reaction and attitude toward the program contents, instructors, facility and handout as perceived by the participants. The problem of this study is to evaluate the effectiveness of the Ductile Iron Casting Training program offered by the Industrial Technology department of a Midwestern University to …

Optical Spray Painting Practice And Training System, Richard J. Klein Ii

Patents (University of Northern Iowa)

An optical spray painting practice gun emits a shaped optical beam onto a practice surface to simulate an actual paint spray on the surface. The gun preferably uses a class 2 diode laser to generate a laser beam which is reshaped by a collimating lens into a diverging beam that illuminates the practice surface. The collimating lens creates an elongated image on the practice surface having a length corresponding linearly to the distance of the practice gun nozzle to the practice surface as with a conventional spray gun. The illuminated image distorts when the practice gun is not perpendicular to …

Paint Gun Incorporating A Laser Device, Richard J. Klein Ii, Douglas L. Sevey

Patents (University of Northern Iowa)

A spray gun for applying a liquid spray coating, such as paint, to a surface incorporates a light source and detection system for analyzing the position of the spray gun relative to a worksurface in order to optimize application of the coating to the surface. The light source is preferably in the form of a laser which emits a beam of light toward the worksurface. The laser is interconnected with the housing of the spray gun in a location over the spray gun handle so as not to effect the center of gravity of the spray gun. Optical sensors are …