Materials Science and Engineering Commons^™

Effect Of Solder Joint Flux Residue On Medical Guide Wire Performance, Rebecca Lisberg, Enlly Bugarin Rodriguez

Materials Engineering

The effect of residual soldering flux on the mechanical properties of 304 stainless-steel core medical guide wires was analyzed. A soldering process joins the metallic components of the distal end of a medical guide wire product. Acidic soldering flux is used to prepare the surfaces of the metallic substrates. Manufacturing protocol utilizes an ultrasonic bath to remove excess flux from the soldered joints. Sample groups underwent different levels of cleaning: no cleaning, partial cleaning, and full ultrasonic bath cleaning to obtain varying residual flux levels. Experimental sample groups underwent corrosion acceleration in an environmental chamber at 37°C and 85% relative …

Functionalization Of 2d-Zno For Selective Gas Sensing: First-Principles Analysis, Alaa F. M. Shaheen

Mechanical Engineering Theses

The scope of this MSc thesis is to theoretically search for suitable materials and relevant factors (e.g., dopants and catalysts) to induce gas sensing (GS) selectivity towards harmful gases such as H₂, H₂S, and CO₂, under ambient conditions. We chose as material 2D-ZnO Honeycomb in the form of nanoribbon (ZnO-NR), which is very promising in the gas sensing applications. We employed a state-of-the-art computational method, based on a combination of the density-functional theory (DFT) and the Non-Equilibrium Green’s Functions (NEGF) formalism, which both are incorporated in Atomistic Toolkit (ATK) package. This package is famous …

Effect Of Slm Build Parameters On The Compressive Properties Of 304l Stainless Steel, Okanmisope Fashanu, Mario F. Buchely, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Heath Misak, Michael Walker

Materials Science and Engineering Faculty Research & Creative Works

Selective laser melting (SLM) is well suited for the efficient manufacturing of complex structures because of its manufacturing methodology. The optimized process parameters for each alloy has been a cause for debate in recent years. In this study, the hatch angle and build orientation were investigated. 304L stainless steel samples were manufactured using three hatch angles (0◦, 67◦, and 105◦) in three build orientations (x-, y-, and z-direction) and tested in compression. Analysis of variance and Tukey's test were used to evaluate the obtained results. Results showed that the measured compressive yield strength and plastic flow stress varied when the …

Maximizing Poly(3-Butylthiophene-2,5-Diyl) Electrical Conductivity By Maximizing Transcrystal Growth, Edward Alexander Bicknell

Materials Engineering

Polymers are generally considered electrical insulators. Despite this, research in the mid 1970’s found that polymers consisting of a conjugated backbone structure could become electrically conductive upon doping.1 The conjugated polymer analyzed for this project was poly(3-butylthiophene-2,5-diyl) (P3BT). Transcrystals have been found as a way to promote electrical conductivity through mechanisms including π bond atomic orbital overlap and electron mobility.2 In theory, maximizing transcrystal length would also maximize P3BT electrical conductivity, increasing its applicable use in electronic devices. The goal of this project was to determine a methodological way to maximize P3BT electrical conductivity by producing the longest transcrystal length …

Effect Of Overaging On Tensile Properties Of 2219-T852 Aluminum, Austin Bitter, Tristan Koyamatsu

Materials Engineering

This project investigated the overaging performance of aluminum alloy 2219-T852 for use in high temperature applications. 2219 aluminum is an alloy containing 5.8 to 6.8 percent copper, and is classified as a high strength age hardenable alloy. The sponsor for this project, Weber Metals, hopes to use 2219 Al to replace titanium in certain applications above the thermal limits of typical high strength Al. To test its performance, they manufactured round tensile samples and delivered them in peak aged, T852 condition. These samples were then overaged at a range of times and temperatures. The times in this experiment were one …

Weld Fracture Between C450 Stainless And C300 Maraging Steels In Golf Club Heads, Emily Oreste, Shea Costner

Materials Engineering

This project studied fractures along the weld on the face of TaylorMade metalwood golf clubs. The weld joint investigated was between investment cast C450 stainless steel and hot rolled C300 maraging steel that had been joined by plasma arc welding (PAW). Cracking in the welds between these two metals was discovered during in-house prototype testing. To understand the differences between the clubs with intact weld joints and clubs with fractured weld joints, the microstructures throughout the weld zones were imaged and a grid of microhardness values of the entire sample cross-section was generated. The images and hardness values were analyzed …

Rotating Beam Fatigue Of Forged 2219-T852 Aluminum Alloy, Julio Escamilla, Madison Reed

Materials Engineering

2219 aluminum has been used extensively in aerospace applications due to its ability to retain strength in large section thicknesses, thus making it ideal for large forgings. However, the Metallic Materials Properties Development and Standardization (MMPDS) handbook, a source of design data for aerospace industry applications, lacks information on 2219 in the T852 condition, particularly concerning the behavior of the alloy under cyclic loading conditions. Data was collected for forgings of 2219-T852 aluminum as produced by Weber Metals to determine the fatigue life of the alloy-temper combination and to assess the effects of forge thickness and orientation on fatigue life. …

Supercapacitors With Gate Electrodes, Tazima Selim Chowdhury

Dissertations

A new approach to improve the capacitance of supercapacitors (SC) is proposed in this study. A typical SC is composed of an anode and a cathode; a separator in between them assures an unintentional discharge of the capacitor. The study focuses on a family of structured separators, either electronically active or passive which are called gates. An active structured separator layer has been fabricated and analyzed. The structured separator has characteristics of electrical diode and is fabricated out of functionalized carbon nanotubes (CNT). Improvement of the overall capacitance of SC, equipped with either active or passive structured separators demonstrated a …

Epitaxial Growth Of Iii-Nitride Nanostructures And Their Optoelectronic Applications, Moab Rajan Philip

Dissertations

Light-emitting diodes (LEDs) using III-nitride nanowire heterostructures have been intensively studied as promising candidates for future phosphor-free solid-state lighting and full-color displays. Compared to conventional GaN-based planar LEDs, III-nitride nanowire LEDs exhibit numerous advantages including greatly reduced dislocation densities, polarization fields, and quantum-confined Stark effect due to the effective lateral stress relaxation, promising high efficiency full-color LEDs. Beside these advantages, however, several factors have been identified as the limiting factors for further enhancing the nanowire LED quantum efficiency and light output power. Some of the most probable causes have been identified as due to the lack of carrier confinement in …

N8- Polynitrogen Stabilized On Carbon-Based Supports As Metal-Free Electrocatalyst For Oxygen Reduction Reaction In Fuel Cells, Zhenhua Yao

Dissertations

The sluggish oxygen reduction reaction (ORR) kinetics at the cathode is one of the key factors limiting the performance of polymer electrolyte membrane fuel cell (PEMFC). Platinum-based materials are the most widely studied catalysts for this ORR reaction while their large-scale practical application in fuel cells is hindered due to their scarcity and low stability. Therefore, highly active, low cost and robust non-Pt catalysts are being developed to overcome the drawbacks. Recently, a novel polynitrogen N8- (PN) stabilized on multiwall carbon nanotube (MWNT) was synthesized under ambient condition for the first time by our group and demonstrated high ORR activities. …

Surface-Enhanced Raman Detection Of Glucose On Several Novel Substrates For Biosensing Applications, Laila Saad Alqarni

Dissertations

The small normal Raman cross-section of glucose is considered to be a major challenge for its detection by Surface Enhanced Raman Spectroscopy (SERS) for medical applications. These applications include blood glucose level monitoring of diabetic patients and evaluation of patients with other medical conditions, since glucose is a marker for many human diseases. This dissertation focuses on Surface-Enhanced Raman Scattering primarily for the detection of glucose. Some experiments also are carried out for the detection of the corresponding enzyme glucose oxidase that is used in electrochemical glucose sensors and in biofuel cells. This project explores the possibility of utilizing Surface …

Characteristics Of Bi-Metallic Interfaces Formed During Direct Energy Deposition Additive Manufacturing Processing, Ryan Anderson, Jordan Terrel, Judy Schneider, Sean Thompson, Paul Gradl

PRC-Affiliated Research

Various additive manufacturing processes are being evaluated to reduce the time and cost for fabrication of low volume, complex, and multifunctional assemblies. This study evaluated two direct energy deposition processes for the fabrication of large bi-metallic structures. The materials evaluated were Inconel 625 and copper alloy C18150, which are used in various high heat flux applications. Inconel was deposited onto the C18150 substrate using blown powder and wire-fed processes. Complete bonding was obtained in both processes and the resulting interfaces were evaluated using microscopy and indentation testing. Differences were observed in the interface region suggesting the kinetic energy of the …

Characteristics Of Bi-Metallic Interfaces Formed During Direct Energy Deposition Additive Manufacturing Processing, Ryan Anderson, Jordan Terrel, Judy Schneider, Sean Thompson, Paul Gradl

PRC-Affiliated Research

Various additive manufacturing processes are being evaluated to reduce the time and cost for fabrication of low volume, complex, and multifunctional assemblies. This study evaluated two direct energy deposition processes for the fabrication of large bi-metallic structures. The materials evaluated were Inconel 625 and copper alloy C18150, which are used in various high heat flux applications. Inconel was deposited onto the C18150 substrate using blown powder and wire-fed processes. Complete bonding was obtained in both processes and the resulting interfaces were evaluated using microscopy and indentation testing. Differences were observed in the interface region suggesting the kinetic energy of the …

Characteristics Of Bi-Metallic Interfaces Formed During Direct Energy Deposition Additive Manufacturing Processing, Ryan Anderson, Jordan Terrel, Judy Schneider, Sean Thompson, Paul Gradl

PRC-Affiliated Research

Various additive manufacturing processes are being evaluated to reduce the time and cost for fabrication of low volume, complex, and multifunctional assemblies. This study evaluated two direct energy deposition processes for the fabrication of large bi-metallic structures. The materials evaluated were Inconel 625 and copper alloy C18150, which are used in various high heat flux applications. Inconel was deposited onto the C18150 substrate using blown powder and wire-fed processes. Complete bonding was obtained in both processes and the resulting interfaces were evaluated using microscopy and indentation testing. Differences were observed in the interface region suggesting the kinetic energy of the …

An Electrical Matlab Model Of Plasma Electrolytic Oxidation, Huize Xue

Theses

Plasma Electrolytic Oxidation (PEO), a part of Plasma electrolytic Deposition (PED), has been developing for surface modification of metallic materials in the past 20 years. During PEO process, sample always connect with anode of DC power source, under high temperature, accelerating process of oxidation reaction to from an average and dense oxidation film. A general passage, Plasma electrolysis for surface engineering, written by A.L. Yerokhin, X. Nie gives us a trend of what happened during PEO process but did not determine specific material and value. Linxin Zhu’s Development of PEO invent a new boiling system and investigated relationship between surface …

Highly Effective Geni Alloy Contact Diffusion Barrier For Bisbte Long-Term Thermal Exposure, Erdong Song, Brian S. Swartzentruber, Chowdary R. Koripella, Julio A. Martinez

Publications and Research

A GeNi alloy diffusion barrier for contacts on bismuth antimony telluride is proposed. Multiple gold contact diffusion barriers were tested at different thermal aging conditions in air and reducing atmospheres. Among all diffusion barriers, the GeNi alloy barrier shows the best performance for bulk samples with no substantial degradation of the contact resistance, no contact color change, and no change of thermoelectric properties. We observed DAu−GeNi = (9.8 ± 2.7) × 10−20 m2/s within the GeNi alloy barrier, which is 4 times smaller than DAu−BiSbTe. The presence of the initial Ge layer also proves to be effective in reducing nickel …

Investigating The Rapid Curing Possibility Of Geopolymer Concrete, Ashlesh Banjara

Master's Theses

Recent studies of heat-cured fly ash based green geopolymer concrete have shown its suitability for fabrication of structural members. Fabrication of these structural members requires continuous moderate heating (145°F) for 24 hrs, and an oven essential, for a large member can quickly turn into an energy guzzler, potentially eliminating the green credentials of the product. The proposed research involves the development of a frontal polymerization (FP) method that achieves rapid curing of geopolymer at ambient condition after short-term heat application. Initial work shows thermal FP in geopolymer is a possibility and might be a solution to the problem. The process …

Performance Enhancement Of Ssi-Leds And Geometrically Confinement Of Lighting Dots By Using Patterned Wafer Approaches, Shengli Wu, Yiwei Liu, Xiaoning Zhang, Can Yang, Lingguang Liu, Yaogong Wang, Gang Niu

Semiconductor Technology for Ultra Large Scale Integrated Circuits and Thin Film Transistors VII (ULSIC VS TFT 7)

Solid state incandescent light emitting devices (SSI-LEDs) were first demonstrated in 2013 by Kuo’s group, which have the metal-oxide-semiconductor structure and emit white light directly¹. The conductive filaments (CFs) through CAFM figures out that Si wafer has a significant impact on the device performance^{2, 3}, multiplayer dielectric layers structure have also been study to enhance the light emission⁴. We demonstrate two approaches to improve the performance of SSI-LEDs by using patterned wafer in this work.

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Using Thermal Gradient Measurements To Compare Bath Temperature And Agitation Effects On The Quenching Performance Of Palm Oil, Canola Oil And A Conventional Petroleum Oil, Bozidar Matijevic, Bruno F. Canale, Božidar Lišcic, George Totten

Mechanical and Materials Engineering Faculty Publications and Presentations

A proprietary Liscic/Petrofer cylindrical Inconel 600 probe of 50-mm diameter and 200-mm length which was instrumented with three thermocouples on the same radius of the crosssection at the middle of the length was used to determine the differences in quenching performance of two vegetable oils, palm oil and canola oil, and they were compared to a locally produced conventional petroleum oil quenchant. The cooling curves and heat transfer performance of these oils were determined at different bath temperatures and agitation rates. The work was performed at the Quenching Research Centre located at the Faculty for Mechanical Engineering, University of Zagreb, …

Triperyleno[3,3,3]Propellane Triimides: Achieving A New Generation Of Quasi-D3h Symmetric Nanostructures In Organic Electronics, Lingling Lv, Josiah Roberts, Chengyi Xiao, Zhenmei Jia, Wei Jiang, Chad Risko, Lei Zhang

Chemistry Faculty Publications

Rigid three-dimensional (3D) polycyclic aromatic hydrocarbons (PAHs), in particular 3D nanographenes, have garnered interest due to their potential use in semiconductor applications and as models to study through-bond and through-space electronic interactions. Herein we report the development of a novel 3D-symmetric rylene imide building block, triperyleno[3,3,3]propellane triimides (6), that possesses three perylene monoimide subunits fused on a propellane. This building block shows several promising characteristics, including high solubility, large π-surfaces, electron-accepting capabilities, and a variety of reactive sites. Further, the building block is compatible with different reactions to readily yield quasi-D_3h symmetric nanostructures (9, …