Engineering Commons^™

Evaluation Of Inconel 718 Laser Powder Bed Fusion Angled Wall Artifact, Laura Itzel Marquez

Open Access Theses & Dissertations

This research investigates the mechanical properties and microstructural characteristics of Inconel 718 specimens fabricated using different additive manufacturing (AM) systems, focusing on the influence of build orientation. A total of 16 samples were constructed at 45, 60, and 90 degrees to the build platform and analyzed to ascertain variations in mechanical strength, encompassing elongation at break, ultimate tensile strength (UTS), yield stress, and hardness. The comprehensive statistical analysis employs robust methods to quantify the effects of printing parameters on the performance of the builds, thereby identifying the most influential factors in AM processes. Additionally, microstructural analysis through advanced imaging techniques, …

Inkjet-Printed Electrochemical Sensors For Lead Detection, Annatoma Arif

Open Access Theses & Dissertations

This PhD dissertation research has developed a simple, miniaturized, sensitive, selective, reproducible, and disposable 3D (inkjet printed – additive manufacturing technology) gold (Au) plated electrochemical sensor (ECS) on shape memory polymer (SMP) for aqueous lead detection. This technology has shown promising performance in the application of electrochemical sensing (lead (II) detection) due to increased effective electrode surface area (7.25 mm^2 ± 0.15 mm^2) despite miniaturizing lateral surface area (4.19 mm^2). The design, fabrication processes, optimization including bismuth functionalization, evaluation, uncertainty analysis, and cost analysis of the novel SMP based inkjet printed Au plated sensor have been delineated in this manuscript …

Metal Additive Microfabrication Of Semiconductor Packages With Inbuilt Thermal Management System, Bhushan Lohani

Open Access Theses & Dissertations

Moore’s law describes the development capabilities in electronics manufacturing. Although his estimation held for decades, at present, the doubling of components every two years seems to be approaching a halt. The assessment was based on the miniaturization of transistors to create space for more. Miniaturization led to higher component density, decreased cost, lowered power consumption, and compactness. However, it also came with high current density, increased Joule heating, and reduced critical charge. One of the limiting factors is the heat generated from such devices, which is heavily discussed in International Roadmap for Devices and Systems (IRDS) and International Technology Roadmap …

Additive Manufacturing Of Binary And Ternary Shape Memory Polyester Blends As A Pathway Towards High Entropy Polymer Systems., Luis Eduardo Lares Carrillo

Open Access Theses & Dissertations

The purpose of this work is to incorporate additive manufacturing technology (AM) in the development of shape memory polymer blends. Two polyester blend systems were developed, one binary and the other ternary. The binary blend consisted of polycaprolactone (PCL) and thermoplastic polyurethane (TPU) and the ternary blend was composed of PCL, TPU and polylactic acid (PLA). Test specimens were fabricated with the AM technology of fused filament fabrication (FFF). Several tests were performed to characterize the mechanical and shape memory properties. A dynamic mechanical analyzer (DMA) was first used to establish the shape recovery temperature. Tensile testing was carried out …

A Method For Measuring The Spectral Emissivity Of Metal Powders At Different Temperatures And Applications In Laser Powder Bed Fusion, Emmanuel Levario

Open Access Theses & Dissertations

Radiation thermometry monitoring methods used in powder bed fusion additive manufacturing (PBF-AM) are becoming increasingly more popular for quality assurance and repeatability. The dynamic nature of the PBF process and a lack of accuracy of metrics being captured for temperature monitoring lend great difficulty in the successful implementation of in-situ monitoring. There is currently no data on the emissivity, a metric used in non-contact temperature measurements, for metal powders used in AM. This work describes a method for measuring the spectral emissivity for metal powder sizes commonly used in AM using a multi-wavelength (MW), FMPI SpectroPyrometer, calibrated within the spectral …

Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos

Open Access Theses & Dissertations

An interpenetrating polymer network (IPN) for cation exchange applications was synthesized from a blend of styrene-ethylene/butylene-styrene (SEBS) and acrylonitrile butadiene styrene (ABS), which was 3D printed, grafted with crosslinked polystyrene (PS), and sulfonated. A method for styrene grafting was applied to reduce the damage to polymer phases caused by the sulfonation reaction. Styrene and divinylbenzene monomers were introduced to the IPN and induced with heat treatment to polymerize in situ. The graft copolymerization reaction was enhanced with varying quantities of benzoyl peroxide as a chemical initiator. The samples were subsequently sulfonated with chlorosulfonic acid in dichloroethane and functionalized for ion …

Processes & Toolchain For Automation Of Hybrid Direct-Write 3d Printing, Gilbert Thomas Carranza

Open Access Theses & Dissertations

Hybrid 3D printing has evolved from a means to rapidly prototype devices to a fully viable means of manufacturing final products. In particular, electronic and electromagnetic devices have been a focus of hybrid 3D printing multi material structures. However, while the hardware capabilities have been around for years, the software capabilities have only begun to catch up. A process and toolchain for hybrid 3D printing is critically needed.This work details a process and toolchain for hybrid 3D printing metal dielectric structures. In it, a basic slicing algorithm is shown along with off-axis printing and conformal printing for arbitrary curvatures. These …

Direct Ink Write And Thermomechanical Characterization Of Thermoset Composites, Sergio Dante Favela

Open Access Theses & Dissertations

This research will be divided into two sections. The first section discusses direct ink writing and thermomechanical characterization for thermoset composites. The thermoset ink is prepared with fillers aiding the printing process by modifying the rheology of the ink and geometry retention by allowing for the part to have an initial UV cure step. Three specimen formulations with different weight percentages were printed by material extrusion in the shape of tensile specimens following ASTM standard D638 to characterize the mechanical properties at room temperature, 100â?? and 200â??. Furthermore, the ink resin was characterized through DSC, TGA, and rheology testing. The …

3d Printing Of Ceramics And Polymers For Engineering Applications, Jesus Javier Mata

Open Access Theses & Dissertations

The Additive Manufacturing industry, in the last years [1] has shown a great push with the development and inclusion of new technologies that have enable the engineering world to achieve great advances. As a consequence of this surge of new technology deriving from the basic principle that conforms additive manufacturing, according to the ASTM a total of seven categories have been defined. The inclusion of these new technologies and the ongoing advances in material implementation has provided the industry with a degree of freedom never seen before, leading to the creation of new solutions to existing problems that seemed impossible …

Suitability Of Low-Cost Additive Manufacturing For Polymer Electrolyte Fuel Cells, David Alexander

Open Access Theses & Dissertations

The purpose of this dissertation is to study the feasibility of low-cost additive manufacturing to fabricate polymer electrolyte fuel cell bipolar plate materials. Traditional manufacturing techniques include molding, milling, hollow embossing, hydro-forming, rolling, and electromagnetic forming. These processes are employed when a design has been selected due to higher costs at low volumes. The combination of high initial costs and bipolar plates being the most expensive component of the polymer electrolyte fuel cell creates incentive to mitigate this obstacle. The feasibility of low-cost additive manufactured bipolar plates will be proven by fabrication, post-processing, and characterization of printed test specimen. The …

Material Synthesis And Machine Learning For Additive Manufacturing, Jaime Eduardo Regis

Open Access Theses & Dissertations

The goal of this research was to address three key challenges in additive manufacturing (AM), the need for feedstock material, minimal end-use fabrication from lack of functionality in commercially available materials, and the need for qualification and property prediction in printed structures. The near ultraviolet-light assisted green reduction of graphene oxide through L-ascorbic acid was studied with to address the issue of low part strength in additively manufactured parts by providing a functional filler that can strengthen the polymer matrix. The synthesis of self-healing epoxy vitrimers was done to adapt high strength materials with recyclable properties for compatibility with AM …

All-In-One Multi3d System: Exploring Potential Of 5-Axis Material Extrusion Additive Manufacturing, Angel Vega

Open Access Theses & Dissertations

Additive Manufacturing (AM) has experienced consistent growth since its inception across its seven process categories, especially Material Extrusion (MEX) with systems that can be seen in commercial and industrial settings. As MEX evolves, innovation can be traced in the growing variety of available process materials and new system capabilities leading to greater interest in the technology across various industries including automotive, aerospace and even nuclear weapons. This has created an increasing demand for end-use parts from MEX systems leading to more complex machines with additional Degrees of Freedom (DoF), specialized workflows, and expanded post processing that address the drawbacks of …

Electron Beam Melted Parameter Development Of Pure Tungsten & Post-Processing Hip And Heat Treatment Of Gamma Titanium Aluminide, Kurtis Isami Watanabe

Open Access Theses & Dissertations

Pure tungsten is a refractory metal and has been gaining interest for the use in nuclear fusion reactors as a plasma facing material. Titanium Aluminide (TiAl) has been growing in popularity as a possibly to phase out Nickel based superalloys due to its high specific strength at elevated temperatures. These two materials suffer from poor machinability due to being brittle at room temperature. Additive manufacturing (AM) is a recently developed manufacturing method that is fundamentally different than formative or subtractive. AM is a layer-by-layer process that has the potential to manufacture metals to a near net shape. Since the AM …

Development Of A Laser Solder Process For Use With Material Extrusion Additive Manufacturing And Rapid Electronics Prototyping In Embedded Sensing Applications, Emerson Roland Armendariz

Open Access Theses & Dissertations

Industrial and rapid prototyping (RP) trends toward miniaturization of electronic devices containing temperature sensitive electronics and surrounding materials are calling for highly controllable, selective laser soldering technologies. Laser soldering is a non-contact technique that eliminates the risk of marring or damaging sensitive components by precisely focusing a laser beam on a solder filler alloy, leading to a fast and non-destructive electrical joint. Using the benefits of accurate and controlled heat delivery via inexpensive low power laser diodes (LPDL's) in conjunction with ever-increasing additive manufacturing capability in producing complex internal features and geometries, development and testing of a laser application system …

Multiscale And Multimaterial 3d Printing: Impact Of Feedstock Properties And Processing Parameters On Printed Parts, Kazi Md Masum Billah

Open Access Theses & Dissertations

Material extrusion additive manufacturing (AM) technology is one of the most commonly used technology to fabricate functional prototypes and end-use application parts with custom design. The evolution of the extrusion technology led this particular AM process to grow in many aspects such as new materials development, new design thinking, fabrication of parts in multiscale length, and manufacturing of monolithic parts with multiple functionalities. The research presented in this Dissertation results in the creation of knowledge in material extrusion AM technology with the length scale of production-grade to large-scale 3D printing machine those were used to enable the fabrication of multimaterial …

Multi-Wavelength Pyrometry For Emissivity Mapping And Accurate Surface Temperature Measurement In Powder Bed Fusion Systems, Md Moinuddin Shuvo

Open Access Theses & Dissertations

Accurate surface temperature measurement within powder bed fusion (PBF) systems during fabrication remains elusive for many reasons, despite the importance of knowing temperature for improving part quality, process control, repeatability and reproducibility, simulation capabilities, and more. Multi-wavelength (MW) pyrometry has been used previously to measure off-axis temperatures of a small region (~2.6mm in diameter) within an electron beam PBF (EBPBF) system. While this small region measurement makes it difficult to get a full field temperature map of the powder bed, it also allows for inline (on-axis) with laser temperature measurements for laser PBF (LPBF) systems. The MW pyrometry technique determines …

Development Of Recepticals And Joints For Embedded Electronic Components Inserted During Print Via Hybrid Thermoplastic-Based Additive Manufacturing, Leonardo Isaac Gutierrez Sierra

Open Access Theses & Dissertations

The use of hybrid additive manufacturing (AM) systems is a novel approach in the fabrication of multi-functional parts. 3D printed electronics are an example of multi-functional parts fabricated using the Foundry Multi3D System, a hybrid AM system. Previous research has demonstrated the capabilities of the system by manufacturing RF antennas and satellite panels with embedded electronics, to name a few. However, research to identify design clearances and establish a manufacturing process plan had not been performed. The purpose of this manuscript is to determine the correct clearances for foreign components to be inserted unto a partially printed substrate. Besides this …

Mechanical Performance Of Ebm Ti-6al-2sn-4zr-2mo Influenced By The Effects Of Different Hot Isostatic Pressing Treatments, Miguel Lopez

Open Access Theses & Dissertations

Electron Beam Melting (EBM) is an additive manufacturing process that presents a lower level of internal defects in comparison to Selective Laser Melting (SLM). Pairing Hot Isostatic Pressing (HIP) with Additive Manufactured metal parts, sub-surface voids can be eliminated through high pressure and temperature. This significantly improves fatigue life, impact toughness, creep, rupture strength, and tensile ductility. In this investigation, Ti-6Al-2Sn-4Zr-2Mo samples manufactured in the Arcam's Q20 system will be tested as per ASTM E8 Standard Test Methods for Tension Testing of Metallic Materials. Different variants of Hot Isostatic Pressing (HIP) treatments were analyzed and compared. Tensile testing was performed …

Development Of Actuators Using Material Extrusion Additive Manufacturing With Embedded Shape Memory Alloy Wire, Alfonso Fernandez

Open Access Theses & Dissertations

Over the past several decades, the advancements in Additive Manufacturing (AM) technologies have opened a wide variety of applications where AM can be used. Some examples of these advancements are the introduction of automatic wire embedding capabilities, the introduction of multi-material processing and the printing of thermoplastic elastomers. With the availability of these advancements, it is now possible to create spark-free, dust-free actuation mechanisms for applications where it is crucial that no spark is generated (i.e. space shuttle fuel valve).

In this research, a Lulzbot TAZ 6 desktop material extrusion system was utilized to print parts out of Plasticized Copolymer …

Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose

Open Access Theses & Dissertations

Mankind throughout history has possessed an innate characteristic to explore, migrating to new frontiers.The requirement for this travel is most broadly associated with the need to pursue more resources. Rockets have been used as a means of weapons since the Sung Dynasty in the thirteenth empire and have now been integrated for travel/transport. The sophistication of rocketry and propulsion has reached a level to where it is plausible that mankind will be a multi-planetary species. The space industry has grown significantly with the advancement of the sophistication of these rocket technologies. However, a specific challenge to overcome in the space …

In Situ Selective Nitriding Using An Open Source Laser Powder Bed Fusion System, Andres Gerardo Navarro

Open Access Theses & Dissertations

Conventional forms of nitriding titanium limit the locations to surfaces, limiting applications to simple coatings. Additive manufacturing methods provide the opportunity for surface coating methods to be utilized in a layer by layer fabrication method and increase the uses of nitrides. Laser powder bed fusion (LPBF) in particular, provides a fabrication environment with sufficient energy to allow for material nitriding as well as the flexibility of being able to utilize a variety of materials and shielding gases for processing. This project utilizes an AconityONE open source LPBF system with custom laser parameter settings to fabricate and nitride Ti-6Al-4V substrates. This …

Direct Write 3d Printing Of Functional Ceramics, Jorge Angel Diaz

Open Access Theses & Dissertations

Humidity sensors are used in many industries and are important for ensuring quality and safety. Ceramic sensors are preferred because of their quick response time, ability to withstand high temperatures and excellent Chemical and mechanical stability. The manufacturing world has been moving toward additive manufacturing which is a form of synthesizing 3D tangible layer by layer in witch minimal waste is produced. Additive manufacturing also is known as 3D printing has opened new possibilities to design engineers by giving them design freedom and access to the layers of a part to allow embedded sensors. There is a category of ceramics …

Impact Of Temperature And Screw Speed On Material Meso-Structure And Tensile Strength In Large Area Pellet-Fed Additive Manufacturing, Xavier Jimenez Guzman

Open Access Theses & Dissertations

Evolution in additive manufacturing, specifically in material extrusion, has resulted in large-scale machines capable of extruding thermoplastic-matrix composite materials in higher volumes to fabricate products for large-scale applications. As with small- and medium-scale material extrusion, the properties of the final product often correlate directly with the bevy of print parameters employed. The current research was performed to evaluate the effects of the screw speed and temperature on an ABS 20%wt. carbon fiber thermoplastic processed on a Big Area Additive Manufacturing (BAAM, Cincinnati Inc) machine. Five screw speeds (50, 150, 250, 350 and 400 rpm) and three extruder temperature profiles were …

A New Approach To Multiplanar, Real-Time Simulation Of Physiological Knee Loads And Synthetic Knee Components Augmented By Local Composition Control In Fused Filament Fabrication, Joshua Taylor Green

Open Access Theses & Dissertations

Despite numerous advances in biomedical engineering, few developments in surgical simulation have been made outside of computational models. Cadavers remain the primary media on which surgical research and simulation is conducted. Most attempts to quantify the effects of orthopedic surgical methods fail to achieve statistical significance due to limited quantities of cadaver specimen, large variations among the cadaver population, and a lack of repeatability among measurement techniques. The general purpose of the research covered in this dissertation is to develop repeatable simulation of physiological loads and develop techniques to fabricate a synthetic-based replacement of cadaver specimens. Future work applying this …

Development Of A Desktop Material Extrusion 3d Printer With Wire Embedding Capabilities, Jose Francisco Motta

Open Access Theses & Dissertations

Printed circuit boards (PCB) have been widely used as a permanent solution for generating complex circuitries to power electronic devices. Over the years, PCB boards have proved to be reliable when powering electronic devices. However, when fabricating a printed circuit board, one must outsource to fabricate the boards when in prototype phase. Therefore, the risk of intellectual property theft and long lead time is an issue. The objective of this Thesis is to develop a hybrid multi-tool desktop material extrusion 3D printer that allows for easy integration (modularity) of tools to generate multi-functional 3D printed components.

The addition of an …

Constitutive Model Development For Additive Manufacturing, Diana Berenice Montes

Open Access Theses & Dissertations

Additive manufacturing (AM) is known worldwide for revolutionizing the development of three-dimensional modeling by reducing the time and increasing the precision of parts. For Powder Bed Fusion research is necessary to reduce concerns in residual stress, porosity and cracking in AM parts. A constitutive model was created in Abaqus to validate material properties of 3D printed Al 6061. Finite element analysis was performed to investigate how properties may affect in the modification of parameters to reduce printing imperfections. Research was made as well in polylactic acid properties for material extrusion to explore its behavior for creep and relaxation. Properties were …

Additive Manufacturing Of Energy Harvesting Material System For Active Wireless Mems, Victor Fernando Elicerio

Open Access Theses & Dissertations

Additive manufacturing (AM - most commonly known as 3D printing) is a fabrication method and aims to increase production efficiency while lowering costs of constructing quality components for industry application when compared to traditional machining. In addition to this, AM possesses capabilities that far exceed machining as complex geometries are achievable through an array of technologies in a wide variety of materials. The AM process begins with a computer aided design (CAD) which creates a design path for a 3D printer to follow. By following this path, components are built from bottom to top in a layer by layer fashion. …

Predictive Modeling On The Piezoelectric Properties Of 3d Printed Functional Nanocomposites Using The Data Analytics Approach, Md Didarul Islam

Open Access Theses & Dissertations

This paper presents research done on prediction modeling using a data analytics approach to determine various factors affecting the piezoelectric properties of the 3D printed pressure sensors. Previously, the material extrusion 3D printing technique was used to fabricate pressure sensors composed of multiwall carbon nanotubes (CNT), barium titanate (BT), and polyvinylidene fluoride (PVDF) using simple fabrication and low-cost methods. This sensor produced a voltage output of 725 mV (0.13 pC/N) which is enough for pressure sensing applications. However, a holistic study to determine impacts of all factors was not carried out in the previous model. In this study, the design …

Design Optimization For Heat Dissipation In Polymer Additive Manufacturing With Joule Heating, Tania Alejandra Ventura

Open Access Theses & Dissertations

Nowadays, the use of additive manufacturing (AM) is mainly focused on the production of prototypes with the purpose of evaluating a design. This industry has become a subject of constant reinvention; in fact, an emerging application of AM is focused on creating parts with embedded electronics. However, the development of both traditional and additive manufactured electronics has led to an increase in power densities and size reduction. Consequently, thermal management has become essential in electronics, as overheating decreases reliability of the component leading to a premature failure.

In this study, a polycarbonate component design with integral electrical circuitry that is …

Comprehensive Finite Element Modeling Of Ti-6al-4v Cellular Solids Fabricated By Electron Beam Melting, Edel Arrieta

Open Access Theses & Dissertations

Additive manufacturing permits the fabrication of cellular metals which are materials that can be highly customizable and possess multiple and extraordinary properties such as damage tolerance, metamorphic and auxetic behaviors, and high specific stiffness. This makes them the subject of interest for innovative applications. With interest in these materials for energy absorption applications, this work presents the development of nonlinear finite element models in commercial software platforms (MSC Patran/Nastran) that permit the analysis of the deformation mechanisms of these materials under compressive loads. In the development of these models, a detailed multiscale study on the different factors affecting the response …