Materials Science and Engineering Commons^™

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 …

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons

Mechanical Engineering

Lawrence Livermore National Laboratories (LLNL) has several steps in the production process for ceramic nanofiber tubes that they would like to improve - electrospinning, cutting, rolling, sealing and heat treating. We undertook the challenge to deliver LLNL with a semi-automated process that efficiently integrates the steps of cutting, rolling, and sealing to save time and improve control over end dimensions. In this document, we discuss the technical background of the manufacturing steps currently followed to create nanofiber tubes, identify which steps are incorporated in our prototype and explain how they will interface with one another, define the design requirements, present …

Modifying Casting Parameters To Improve The High Temperature Ductility Of Investment Cast Nickel-Based Superalloy Pwa 1455, Lars Alexander Hedin, Cole Magnum Introligator

Materials Engineering

PCC Structurals, an industry leader in superalloy investment castings, has observed inconsistencies in the stress rupture performance of polycrystalline nickel-based superalloy PWA 1455. PCC has changed their casting parameters to reduce the thermal gradient during cooling but have been unable to correlate these changes with an increase in stress rupture elongation. Metallographic examination of past samples indicated microstructures composed of non- equiaxed dendritic grains with mean diameter of .021 inches along the test axis. A similar study on polycrystalline superalloys has indicated that excessive superheat temperatures above the liquidus can result in large grains identical to those observed, limiting the …

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 …

Transient Analysis Of Diffusion-Induced Deformation In A Viscoelastic Electrode, Yaohong Suo, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

In this study, we analyze the transient diffuse-induced-deformation of an electrode consisting of the conducting polymer polypyrrole (PPY) by using the theories of linear viscoelasticity and diffusion-induced stress. We consider two constitutive relationships with dependence of viscosity on strain rate: Kelvin-Voigt model and three-parameter solid model. A numerical method is used to solve the problem of one-dimensional, transient diffusion-induced-deformation under potentiostatic operation. The numerical results reveal that the maximum displacement occurs at the free surface and the maximum stress occurs at the fixed end. The inertia term causes the stress to increase at the onset of lithiation. The stress decreases …

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 …

Photooxidation Of Biopolymers, Marlon H. Dieguez

Materials Engineering

The lack of degradation of plastic products have imposed problems in the preservation of natural environments and their ecosystems through plastic accumulation. This collection of plastics promotes toxin exposure to wildlife, finding its way into the food chain, affecting both land and marine ecosystems. The project goal is to understand the degradation mechanisms of biodegradable materials and other comparable materials through UV radiation testing. Polylactide (PLA) films and polycarbonate (PC) films will be compared for their relative deterioration from constant UV radiation in a Q-U-V accelerated weather tester for 28 days. Five 3” by 5” samples of 14 mil thick …

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 …

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 …

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.

Please click Additional Files below to see the full abstract.

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, …

Ulsi And Tft Technologies In Industry, Research And Higher Education In France: An Evolution Towards Innovation Resulting From Close And Sustainable Interaction, Olivier Bonnaud

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

The semiconductor industry and associated microelectronic production began in France in the early 1980s as part of the national microelectronics plan launched by the French government to meet the needs of new economic sectors that are heavy users of microelectronic products. Indeed, microelectronic circuits, devices and systems are the key elements of the information technology field, which includes computer and communications capabilities, and application fields such as aerospace, transport, and energy, mainly. Several new technologies had to be developed, corresponding to the first advent of communication tools such as Minitel (ancestor of the web) or credit cards, which then underwent …

The Effect Of Fabric Architecture On The Processing And Properties Of Composites Made By Vacuum Assisted Resin Transfer Molding, Francois Ntakobatagize, Oscar Ntakontagize, Donald A. Klosterman

Chemical and Materials Engineering Faculty Publications

The goal of this research project was to evaluate and compare the effect of fabric architecture on the processing and properties of composites made by Vacuum Assisted Resin Transfer Molding (VARTM). The fabric architectures investigated included plain weave, satin weave, and warp-knit unidirectional. The fiber types included E-glass and standard modulus carbon fiber. Flat panels were fabricated with a lab scale VARTM process using an epoxy resin system. Fabric plies were cut to 45 cm x 30 cm (18 in. x 12 in.), and the number of plies used depended on the fiber areal weight of each fabric to produce …

Mechanical Properties And Applications Of Recycled Polycarbonate Particle Material Extrusion-Based Additive Manufacturing, Matthew J. Reich, Aubrey Woern, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications, Part 1

Past work has shown that particle material extrusion (fused particle fabrication (FPF)/fused granular fabrication (FGF)) has the potential for increasing the use of recycled polymers in 3D printing. This study extends this potential to high-performance (high-mechanical-strength and heat-resistant) polymers using polycarbonate (PC). Recycled PC regrind of approximately 25 mm² was 3D printed with an open-source Gigabot X and analyzed. A temperature and nozzle velocity matrix was used to find useful printing parameters, and a print test was used to maximize the output for a two-temperature stage extruder for PC. ASTM type 4 tensile test geometries as well as ASTM-approved …

Conference Program, Yue Kuo, Junichi Murota, Yasuhiro Fukunaka, Yukiharu Uraoka

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

No abstract provided.

Novel Low Shear 3d Bioreactor For The Scaled Production Of High Purity Human Mesenchymal Stem Cells, Andrew Burns

KGI Theses and Dissertations

Human mesenchymal stem cells are an ideal candidate for stem cell therapies. They have been researched since the 1960’s and can differentiate into many desired functional cell types without undergoing teratogenesis. However, higher yields are needed for a marketable, successful stem cell therapy. To accomplish this, cells will have to be cultured to expand them to therapeutically relevant dosages for multiple patients. Bioreactor production is an ideal method to solve this problem.

The aim of this thesis is to test and validate a novel bioreactor for the cultivation of human mesenchymal stem cells. In this work, we investigate a novel …

Design And Control Of Fiber Encapsulation Additive Manufacturing, Matt Saari

Mechanical Engineering Research Theses and Dissertations

This work presents the design, development, and analysis of the Fiber Encapsulation Additive Manufacturing (FEAM) system developed at the Laboratory for Additive Manufacturing Robotics \& Automation at the Lyle School of Engineering at Southern Methodist University. The innovation introduced by FEAM is the ability to insert a continuous fiber of different material into the flowing extrudate. Correctly positioning the fiber feed inside the extrudate while turning the fiber in arbitrary directions is a critical aspect of the technology. This will allow for the full exploitation of the capabilities of the FEAM technology to produce robotic components that actuate and sense. …

Using Numerical Models Of Dewatering At Coal Ash Impoundments To Understand Cost And Schedule, Peter Bell, Joel Thompson, Don Fuller

World of Coal Ash Proceedings

No abstract provided.

Investigating Ccr Units And Evaluating The Physical Properties Of Ponded Ccr, David Skeggs, Zahra Aghazadeh, Rachel Combs

World of Coal Ash Proceedings

No abstract provided.