Materials Science and Engineering Commons^™

Synthesis And Characterization Of Cobalt-Based Magnetic Nanostructures, Jacob Elkins

Material Science and Engineering Theses - Archive

Co is an attractive element in the development of nanostructured magnetic materials due to its relatively high moment (1.72-1.75 µB) and strong exchange and spin-orbit interactions, and many of these materials have potential in applications such as data recording media, hyperthermia treatments, and nanostructured permanent magnets. In this thesis, magnetic nanostructures of CoFe2O4, Co, and CoNi with controlled size, shape, composition, and crystal structure are synthesized via bottom-up wet chemical methods and their magnetic properties are systematically characterized. Additionally, nanocomposites of exchange-coupled FeCo/CoFe2O4 and Co/FeCo core-shell nanostructures with enhanced magnetizations are prepared and investigated. In order to understand the prominent …

Study Of Interdiffusion And Growth Of Intermetallic Compounds In Bimetallic Layers Of Alpha Brass And Al-Mg Alloy, Ratan Kota

Material Science and Engineering Theses - Archive

This work aims to study the formation of Inter Metallic Compounds (IMC’s) and their growth rate in Brass and Al-Mg alloy. This diffusion couple consists of four elements Aluminum, Copper, Zinc and Magnesium. Aluminum and Copper are major diffusing elements. Brass-Aluminum bimetal is an advanced structural material and used as a cladding material. This bimetal is produced by cold roll bonding and is mechanically bonded. To increase the adhesive strength of these bimetal layers, the sample is subjected to heat treatment which leads to the formation of Inter Metallic Compounds (IMC). Heat treatments are generally done above the recrystallization temperature …

An Investigation On The Corrosion Inhibition Of Brazing Cu-Ag Alloy, Hooman Rahmani

Material Science and Engineering Dissertations - Archive

Adsorption and inhibition behavior of 1,2,3-benzotriazole (BTA) and 2,5-dimercapto-1,3,4-thiadiazole (DMTD) on brazing Cu-Ag alloy was studied in deionized water using corrosion potential measurement, potentiodynamic polarization, adsorption isotherm investigation, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). Pure Ag and pure Cu specimens were included to investigate the mere effect each component has on the alloy’s behavior along with a high copper alloy for comparison purposes. The electrochemical responses show that BTA shifts the corrosion potential of Cu to the noble direction but has the opposite effect for Ag and a mixed behavior for the Cu-Ag alloys. However, DMTD in …

Aqueous Redox Flow Batteries With Boron Doped Diamond As An Electrode., Alex M. Bates

Electronic Theses and Dissertations

As the interest and implementation of renewable energy accelerates, so does that of grid energy storage. It is widely believed that a cost-effective energy storage technology will bring about the proliferation of renewable energy. Redox flow battery (RFB) technology represents a promising solution to cost-effective grid energy storage. Compared to other technologies, RFBs have a long lifetime, high efficiency, are non-flammable, significantly reduce cost, and separately scale power and energy. The separation of power and energy enables increased energy capacity by simply adding electrolyte volume. Of the challenges facing RFB technology, one readily apparent is the cost of the active …

Development Of A Cvd Assisted Pld System For Growing Novel Materials, Sinjan Majumder

Graduate Theses/Dissertations

The fundamental step for development of novel materials like semiconductors involves stacking of layers of thin films of materials with desired properties on a particular substrate. In order to study the properties of these materials for research purposes in the laboratory, development of a clean fabrication technique is essential. PLD is a technique employed for growing thin films using laser ablation of a target material. CVD is an alternate method used to deposit solid materials from a gaseous phase. However, combining these two techniques can enhance plume, gas and laser interaction to facilitate the growth of novel materials with new …

Formula Sae Monocoque Chassis Development, Kc Egger, Brian Ford, Kyle Nagao, Neal Sharma, Donovan Zusalim

Mechanical Engineering

Formula SAE is a collegiate competition hosted by SAE International with the primary goal being to design, manufacture, and race an open wheel race car. The Cal Poly Racing Formula SAE team strives for improvement every race season and has remained competitive as a result. The 2019-2020 management team determined that further research and development towards the chassis would yield the greatest performance benefit for future seasons, as the previous chassis platform limited packaging and mounting options for vehicle subsystems which interfaced with the chassis.

A redesign of the Cal Poly Racing Formula SAE team’s carbon fiber reinforced polymer monocoque …

The Structural And Magnetic Properties Of Nio/Mn(Ni)-Oxide Magnetic Heterostructured Nanocrystals Synthesized Under Varying Ph Values, Abdullah Al Shafe

Graduate Theses/Dissertations

The role of pH on the structural, morphological, and magnetic properties of hydrothermally synthesized NiO-based magnetic heterostructured nanocrystals (MHNCs) is investigated. The NiO nanocrystals were synthesized using a two-step thermal decomposition process whereas the deposition of the surrounding Mn-based phases was accomplished by hydrothermal means at pH values ranging from 2.4 to 7.0. The resulting heterostructured nanocrystals consist of inverted AFM-FiM NiO/±Mn_xNi_1-xO/±Mn₃O₄ bimagnetic/trimagnetic systems. A complete characterization of the MHNCs was carried using XRD, TEM, EDS, MPMS magnetometry and XPS analysis. Structural investigations revealed predominantly faceted MHNCs ranging in size from 24-30 nm …

Performance Of Pld Grown Zno Thin Film As A Thin Film Transistor, Shahidul Asif

Graduate Theses/Dissertations

The performance of ZnO thin film (grown in different parameters) as a thin film transistor (TFT) is the focus of this study. ZnO is renowned for being n-type semiconductor naturally which was utilized in fabricating a thin film transistor here. This thesis is compared the performance of ZnO thin film transistor by growing the thin film using pulsed laser deposition (PLD) on two slightly different substrates at different temperatures in an optimal 0.1 milli bar oxygen pressure which was later analyzed using other material characterization methods. The substrates were both Si (100) but had different resistivity due to different amount …

Ractive Md Simulation On The Formation Of Amorphous Alumina Layer Using Atomic Layer Deposition (Ald), Yuxuan Lu

Graduate Theses/Dissertations

In this study, a systematic study has been performed by using the large-scale classical reactive molecular dynamics (MD) simulations to model the Atomic Layer Deposition (ALD) processes that generated tan ultra-thin and sub-nano meter amorphous alumina. The ALD process employed both water pulse and (Trimethyl-Aluminum) TMA precursors deposited onto the surface of an aluminum wetting layer. The study varied the sizes of the substrate and the concentrations of water/hydroxide precursors with a range of operating temperature to design the most favorable configurations for the subsequent TMA precursors to add onto. The role of crystallographic orientation of the Al wetting layer …

Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong

Boise State University Theses and Dissertations

For magnetic shape memory (MSM) alloys, a magnetic field stimulates a shape change. We use the shape change to build devices such as micro-actuators, sensors, and microfluidic pumps. Currently, (as a novel technology,) devices suffer from some material and magnetic driver shortcomings. Here we address the issues related to operating temperature, repeatability, failure, and magnetic driver development. To increase the operating temperature of the MSM material, we alloyed Fe and Cu to Ni-Mn-Ga. We showed that the element-specific contribution to the valence electron density as parameter systematically determines the effect of each element on the variation of the martensite transformation …

Study Of New Transistor Architecture With Energy Filtering, Nnaemeka Mcdonald Eluagu

Material Science and Engineering Theses - Archive

The thermodynamic limit of the subthreshold slope to 60mV/decade at 300K forces MOSFET devices to use high supply voltages (> 0.5V) and therefore dissipate a lot of energy. This physical limitation of transistors is a direct consequence of thermal excitation of electrons. This study investigates a new transistor architecture capable of suppressing thermally excited electrons using a quantum well as an energy filter. The energy filter consists of a 2nm SiO2 tunneling barrier and a 2nm Quantum Well (QW) layer of Cr2O3 sandwiched between Ni electrodes and a channel of Si. Transistors having this QW energy filter have been fabricated …

Investigation Of High-Temperature Oxidation Resistance Mechanism Of Ceramic Coatings Via Microstructure Analysis, Yi Shen

Material Science and Engineering Dissertations - Archive

Recent developments of ceramic coatings deposited using magnetron reactive sputtering show that these films exhibited superior high-temperature oxidation resistance along with other desirable properties such as high hardness, optical transparency and good electrical conductivity. Detailed microstructure study of these films annealed to high temperatures using transmission electron microscopy (TEM) is deemed necessary as it provides an intuitive vision on the behavior of the materials at elevated temperature, which is essential to further improve their high-temperature oxidation resistance. In this study, Hf-B-Si-C-N films with various compositions that were annealed to various temperatures in both helium and air were subjected to detailed …

Single Molecule Super-Resolution Microscopy Study On The Precision With Which Dna Nanostructures Can Orient Fluorescent Dyes, Brett Michael Ward

Boise State University Theses and Dissertations

DNA nanotechnology enables the rapid, programmable self-assembly of novel structures and devices at the nanoscale. Utilizing the simplicity of Watson-Crick base pairing, DNA nanostructures are capable of assembling a variety of nanoparticles in arbitrary configurations with relative ease. Several emerging opto-electronic systems require a high degree of control of both the position and orientation of component fluorescent molecules, and while DNA nanostructures have demonstrated these capabilities, the precision with which DNA can orient fluorescent molecules is not well understood. Determining these bounds is critical in establishing the viability of DNA nanotechnology as a method of assembling fluorescent molecular networks.

In …

Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor

Boise State University Theses and Dissertations

The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to …

U.S. Greenhouse Gas Emission Bottlenecks: Prioritization Of Targets For Climate Liability, Alexis Pascaris, Joshua M. Pearce

Michigan Tech Publications, Part 1

Due to market failures that allow uncompensated negative externalities from burning fossil fuels, there has been a growing call for climate change-related litigation targeting polluting companies. To determine the most intensive carbon dioxide (CO₂)-emitting facilities in order prioritize liability for climate lawsuits, and risk mitigation strategies for identified companies as well as their insurers and investors, two methods are compared: (1) the conventional point-source method and (2) the proposed bottleneck method, which considers all emissions that a facility enables rather than only what it emits. Results indicate that the top ten CO₂ emission bottlenecks in the U.S. …

Hydrothermal Reaction Synthesis And Characterization Of Zns:Ag Scintillator, Yuchen Shao

All Theses

Thisworkaims at the development of a reactive ultrafiltration membrane scintillator for rapid activity determination and isotopic quantification of waterborne special nuclear materials (SNMs) based on ZnS:Ag. The effects of the pH of the precursor solution on ZnS:Ag synthesized under various conditions of temperature and time by the hydrothermal reaction synthesis method (200℃ for 6 hours, pH from 1 to 12; 100℃ for 2 hours, pH from 7 to 12;60℃ for 6 hours, pH from 7 to 12) were investigated. Samples were characterized on their structure, morphology and luminescence by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) …

Production And Characterization Of Uranium Sol Gel Surrogates Produced With Cerium Acetate And Cerium Nitrate, Matthew Brett Alford

All Dissertations

For the production of ceramic microspheres for future space travel, new methods of processing must be explored. The sol gel method proves promising for the production of uranium-based ceramic microspheres that are consistent enough in size and shape for such an application. A process for producing these microspheres has already been established, but there are avenues for improvement.

Handling of radioactive material like uranium is not always possible or warranted. As such, a non-radioactive surrogate that greatly resembles the processing of its actual radioactive counterpart. Herein this work a cerium-based surrogate is developed to closely resemble an already established process …

Mechanism Of Compaction With Wrinkle Formation During Automatic Stitching Of Dry Fabrics And The Size Effect Of Compression Molded Discontinuous Fiber-Reinforced Composites, Anibal Benjamin Beltran Laredo

Mechanical & Aerospace Engineering Theses & Dissertations

With an ever-increasing demand for composites, more ways of manufacturing them are becoming popular and widely used. Stitching of dry fabrics is an efficient method for improving delamination resistance. Discontinuous fiber reinforced composites can be used as a lightweight alternative material for metals through a process of compression molding, which allows for complex shape manufacturing while offering structural grade mechanical properties.

This study demonstrates how the stitching of dry fabrics can be adapted to more complex surfaces. The consequences of stitching of curvilinear surfaces can result in defect formation. Therefore, to understand the physical formation of possible defects, experimental characterization …

Investigation Of Various Techniques For Controlled Void Formation In Fiberglass/Epoxy Composites, Donald A. Klosterman, Charles Browning, Issa Hakim, Kyle Lach

Chemical and Materials Engineering Faculty Publications

The effect of porosity in composite materials has been studied for years due to its deleterious effects on mechanical properties, especially matrix dominated properties. Currently there is an increasing use of composites in infrastructure worldwide, for example bridge components, residential and building structures, marine structures such as piers and docks, and large industrial chemical tanks. Most of these applications use fiberglass composites. Unfortunately, most of the published literature has focused on carbon fiber composites, in which fiber diameter and gas-fiber interactions are different than fiberglass composites. Therefore, the present study was undertaken to revisit the effect of porosity but specifically …

Synthesis And Characterization Of Bimetallic Gold-Silver (Au-Ag) Nanocatalyst Via Seed Colloid Technique, Berahim Nurafaliana

Student Works (2020-2029)

In the present study, unique catalysts of monometallic gold (Au), silver (Ag) and bimetallic gold-silver (Au-Ag) nanoparticles (NPs) were prepared with different size or diameters by the citrate-thermal reduction and the seed colloidal techniques, respectively. The catalytic nanoparticles were characterized by various advanced analytical techniques such as Ultraviolet-visible spectroscopy (UV-vis), zeta potential, electron dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), High-angle annular dark-field (HAADF) scanning transmission-electron microscopy (STEM) imaging and the energy dispersive spectroscopy (EDS) elemental mapping. The catalytic performance of the nanoparticles were ascertained through the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in …

Comparison Of Pressure-Assist Silver Sintering To Tin Silver Solder Alloy As Die Attach Material In High Power Semiconductor, Tolentino Erik Nino

Student Works (2020-2029)

The research is focused on pressure-assisted silver sintering material that is compared to tin silver solder alloy paste as used in power electronics. Material characterization, electrical tests, and reliability tests were conducted in the experiment. After drying process, it was observed that the Ag sintering paste height was reduced to approximately 40 percent. Die attach shear test showed that the average reading is about from 200 to 600 grams which are already enough to hold the dice before proceeding to the pressure sintering process. X-ray revealed that the void percent for SnAg paste sample is about 1.5 percent while pressure-assist …

Synthesis And Characterization Of Self-Cleaning Hydrophobic Organic Coating, Abdul Jaafar Amirul Syafiq

Student Works (2020-2029)

Three self-cleaning coating systems namely Polydimethylsiloxane (PDMS)/Sylgard, PDMS/3-Aminopropyltriethoxysilane (APTES) (tagged as A1) and A1 blended with nano-Calcium Carbonate (CaCO3) have been synthesised on glass substrates via dip-coating and spray-coating techniques. All of the prepared coatings were dried under ambient condition before being subjected to characterisations and testing(s). The effect of various weight percentages of Sylgard resin that are 5wt.% (S1 coating), 10wt.% (S2 coating), 15wt.% (S3 coating), and 20 wt.% (S4 coating) on the hydrophobicity, self-cleaning property, anti-fog performance and mechanical property of PDMS/Sylgard coating have been discussed in the first section of this thesis. The PDMS/Sylgard coated glass substrates …

Development Of Bragg Fiber Sensor For Corrosion Detection, Cai Hui Tan

Student Works (2020-2029)

Steel corrosion has posed one of the major structural defects in the civil society today. Conventional methods for corrosion monitoring involve high maintenance cost and destructive methods with low accuracy. Recently, Fiber Bragg gratings (FBG) sensor with its high sensitivity in measuring strain and temperature have been widely studied and used in structural health monitoring (SHM). A non-destructive corrosion detection approach based on FBG sensors was developed and tested to monitor corrosion in this research work. The principle of FBG sensing is based on Bragg wavelength shifts that from the corrosion process that induced strain on the FBG due to …

Alumina Ceramic Membrane Incorporated With Graphene Oxide Frameworks For Protein Recovery, Ishak Noor Fauziyah

Student Works (2020-2029)

Alumina ceramic membrane is undergoing rapid development and innovation for protein recovery process. However, the limitation of this membrane type is membrane fouling due to the deposition and adsorption of proteins on the surface and pore walls of the membranes. It is crucial to minimize membrane fouling by reducing interactions between protein and the membrane surface via surface modification technique. Thus, the main objective of this research is to develop an alumina membrane with enhanced antifouling property for protein recovery process. An alumina dope consisting of 57 wt.% alumina loading was used to fabricate two alumina membrane configurations; which are …

Microstructural Evolution And Mechanical Properties Of Ultra-Fine Grained Tubular Components Processed By Severe Plastic Deformation, Mesbah Mohsen

Student Works (2020-2029)

The lightweight alloys have been widely used in various engineering applications such as automotive, aerospace, construction, and biomedical industries due to their low densities, high ductility, formability, and facile machining. However, the emerging trend for materials with high mechanical strength and plasticity hampers the widespread application of these alloys. Over the last two decades, severe plastic deformation (SPD) has been introduced as a promising approach for enhancement of the mechanical performance of the lightweight alloys through microstructural manipulations and grain refinement. However, the SPD techniques have been extensively utilized for the fabrication of non-tubular geometries and the studies on the …

Physical Behavior Of Thermally Affected Bronze And Brass, Samiul Kaiser, Mohammad Salim Kaiser

Journal of Mechanical Engineering Science and Technology (JMEST)

The physical behavior of thermally affected cast copper, aluminum bronze and brass has been studied by subjecting to heating isochronally for one hour at a range of 600°C. It shows that solid-solution hardening takes place into the Al added bronze and Zn added brass metal. Due to heating Al forms hard and brittle intermetallic of copper aluminates into the bronze metal which responses some age-hardening effects. The electrical conductivity of the metals increases initially through heat treatment due to stress relieving and finally decreases due to formation of intermetallic precipitates. The color of the heated samples are also studied through …

Performance Enhancement Of Shell And Tube Heat Exchanger On Parallel Flow With Single Segmental Baffle, Avita Ayu Permanasari, Poppy Puspitasari, Sukarni Sukarni, Retno Wulandari

Journal of Mechanical Engineering Science and Technology (JMEST)

The shell and tube heat exchanger was a tool to exchange the heat energy between fluids with different temperatures that occurred through direct or indirect contact. The energy exchange in fluids could be occurred with the same phase (liquid to liquid or gas to gas) or two fluids with different phase. To date, the process of heat transfer in the industrial field was crucial in machine work. Therefore, there were studies directed to optimize and develop the function and thermal performance of a heat exchanger by adding Baffles to the side of the shell. Vortex flow that occurs with the …

Hardness Evaluation On Ss 316l Joined With Gas Tungsten Arc Welding Under Constant Heat Treatment, Duwi Leksono, Imam Sudjono

Journal of Mechanical Engineering Science and Technology (JMEST)

The purpose of this study is to show the hardness of the GTAW welding results on SS 316L metal with surface heating during the welding process. Observations in this study used SS 316L material with heat temperature regulation on the metal surface of the welding process using heating variations of 100 ℃, 120 ℃ and 140 ℃. The welding process of SS 316L material used a welding joint model uses single V-type welding joint with an angle of 60°, a spacing of 2 mm, a root surface of 1 mm and a thickness of 5 mm. Vickers hardness test was …

The Effect Of Solution Treatment Temperature And Quenching Media Variation In Heat Treatment Process Cu-Zn-Al Shape Memory Alloys On Shape Memory Effect And Microstructures, Wikan Jatimurti, Monica Gayatri K, Mavindra Ramadhani, Rochman Rochiem

Journal of Mechanical Engineering Science and Technology (JMEST)

Shape memory alloys (SMAs) are metal alloys with a reversible ability to recover their shape at a certain temperature after being deformed. This ability referred to as Shape Memory Effect (SME). The application of SMAs such as Ni-Ti and Cu-Zn-Al alloys usually used on automotive, biomedical, etc. The commonly used SMA is Ni-Ti because of its superior SME properties than Cu-Zn-Al, even though the price is quite higher. The SME of Cu-Zn-Al might be improved by increasing the presence of the martensite phase in its microstructure by heat treatment. The heat treatment process given to Cu-21Zn-5Al alloy is a homogenizing, …

Wavelength Decomposition Of Hybrid Additive Manufacturing Power Signals And Their Relationship With Surface Integrity, Xingtao Wang

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

Additive Manufacturing (AM) has been a promising manufacturing technology in industrial applications and gained a massive amount of attention from researchers all over the world. Directed Energy Deposition (DED) is an AM process in which focused thermal energy is used to fuse materials by melting as they are deposited. One of the most significant challenges involved in current metal AM processes is improving repeatability and consistency. Substantial effort has already been invested in this area of research.

In this dissertation, a milling tool not only played a role in subtractive manufacturing but also acted as a method of monitoring the …