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Analysis Of Additively Manufactured Inconel 718 Combustion Behavior In Promoted Oxygen Environments, Dominic George Dieguez
Analysis Of Additively Manufactured Inconel 718 Combustion Behavior In Promoted Oxygen Environments, Dominic George Dieguez
Open Access Theses & Dissertations
Promoted combustion testing is a vital tool for engineers to establish the combustion and flammability characteristics of materials (metallic or otherwise) in oxygen enriched environments. Historically, much of the established data for metallic promoted combustion has been with regards to materials in their cast and wrought forms. However, with the emergence of additive manufacturing as a preferred method of fabrication, the need exists to evaluate how metals in that form behave. Recent testing has demonstrated that even if a metal or alloy is nominally the same with regards to chemistry, flammability between samples in the wrought form can differ significantly …
Extrusion-Based Additive Manufacturing Of Magnetic Heat Exchange Structures For Caloric Applications, Vaibhav Sharma
Extrusion-Based Additive Manufacturing Of Magnetic Heat Exchange Structures For Caloric Applications, Vaibhav Sharma
Theses and Dissertations
Currently, the commercial building sector accounts for 18% of total U.S. end-use energy consumption, of which almost a third was from on-site combustion of fossil fuels for space and water heating. Magnetic heat pumping (MHP) technology is an energy-efficient, sustainable, environmentally-friendly alternative to conventional vapor-compression cooling technology. Several MHP designs today are predicted to be highly energy efficient, on condition that suitable working materials can be developed. This materials challenge has proven to be daunting due to issues associated with intricate synthesis/post-processing protocols and complications related to shaping the mostly brittle magnetocaloric alloys into thin-walled channeled regenerator structures to facilitate …
Short Strand Carbon Fiber Reinforced Polylactic Acid Filament For Additive Manufacturing, Dale Chenoweth, Lukas Seggi, Luke Phillips
Short Strand Carbon Fiber Reinforced Polylactic Acid Filament For Additive Manufacturing, Dale Chenoweth, Lukas Seggi, Luke Phillips
Williams Honors College, Honors Research Projects
In this design project, the additive manufacturing filament of short strand carbon fiber (SSCF) reinforced polylactic acid (PLA) composite was developed. The micro-size, precision cut SSCFs were mixed with the PLA pellets through a melting homogenization process. Through this process the composite material block is cut and divided into pieces for ease of pelletizing. The material block pieces are then pelletized to be fed through the single screw extruder to develop the SSCF-PLA composite filament. The SSCF-PLA filaments were manufactured with a varying amount of SSCF ranging from 0.5% to 10% of the material block's weight. Development of a 1% …
The Effects Of Laser Shock Peening On The Fatigue Life Of Additive Manufactured Alsi10mg, Jacob L. Biddlecom
The Effects Of Laser Shock Peening On The Fatigue Life Of Additive Manufactured Alsi10mg, Jacob L. Biddlecom
All Dissertations
Additive manufacturing (AM) is becoming a manufacturing process that is well established, even with all the resources and attention that has been brought to it, the field is still lacking some key understandings. Currently, there are certain aspects that are difficult to overcome. Some of the intrinsic obstacles include process-induced defects, such as porosity from lack of fusion and gaseous bubble entrapment, as well as complex thermal gradients. These defects can lead to altered material response especially when looking at the fatigue life. The fatigue behaviors of AM components can change from print to print as well as when compared …
Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos
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 …
In-Situ Defect Detection Using Acoustic Vibration Monitoring For Additive Manufacturing Processes, Ali Harake
In-Situ Defect Detection Using Acoustic Vibration Monitoring For Additive Manufacturing Processes, Ali Harake
Master's Theses
The world of additive manufacturing revolves around speed and repeatability. Inherently, the process of 3D printing is plagued with variability that fluctuates with every material and parameter modification. Without proper qualification standards, processes can never become stable enough to produce parts that may be used in aerospace, medical, and construction industries. These industries rely on high quality metrics in order to protect the lives of those who may benefit from them. To establish trust in a process, all points of variation must be controlled and accounted for every part produced. In instances where even the best process controls are enacted, …
Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock
Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock
Electronic Theses and Dissertations
This work focuses on evaluating different modeling approaches and model parameters for thermoplastic AM, with the goal of informing more efficient and effective modeling approaches. First, different modeling approaches were tested and compared to experiments. From this it was found that all three of the modeling approaches provide comparable results and provide similar results to experiments. Then one of the modeling approaches was tested on large scale geometries, and it was found that the model results matched experiments closely. Then the effect of different material properties was evaluated, this was done by performing a fractional factorial design of experiments where …
Material Synthesis And Machine Learning For Additive Manufacturing, Jaime Eduardo Regis
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 …
Suitability Of Low-Cost Additive Manufacturing For Polymer Electrolyte Fuel Cells, David Alexander
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 …
Effect Of Build Geometry And Build Parameters On Microstructure, Fatigue Life, And Tensile Properties Of Additively Manufactured Alloy 718, Anna Dunn
Browse all Theses and Dissertations
Additive Manufacturing (AM), particularly laser powder bed fusion, is being studied for use in critical component applications. Tensile and fatigue testing shows differences when built using different laser powers. However, when fabricated in an as-printed geometry, the gauge sections of the two specimens are different and experience different thermal behavior. This work explores microhardness, microstructure size, Niobium segregation, and porosity from samples made with varying laser power and different build geometry sizes representative of the gauge sections in the tensile and fatigue bars. Results show that microhardness varies spatially across the sample. Smaller diameter metallographic coupons (fatigue diameter) have a …
Recycled Printer Filament, Charlotte Hyland, Troy D. Molinar
Recycled Printer Filament, Charlotte Hyland, Troy D. Molinar
Williams Honors College, Honors Research Projects
The purpose of this research is to examine the effects of recycling PLA filament for 3D printing on its material properties. After examining these effects, PLA and carbon fiber additives were mixed with recycled PLA pellets in different ratios to attempt to regain material properties lost in the recycling process. To complete these findings, an experiment was design and executed.
The research found that tensile strength during multiple iterations of recycling remained mostly unaffected, however, the strain degraded exponentially. In the PLA additive study, high ratios of PLA additive were able to increase the strength and strain properties of the …
Assessing Mechanical Performance Of Dissimilar Steel Systems Made Via Wire-Arc Additive Manufacturing, Obed Daniel Acevedo
Assessing Mechanical Performance Of Dissimilar Steel Systems Made Via Wire-Arc Additive Manufacturing, Obed Daniel Acevedo
Masters Theses
Hot stamping is part of a specific type of metalworking procedure widely used in the automotive industry. This research seeks to help make hot stamp tooling component production more cost-effective by using large-scale additive manufacturing. Additive manufacturing can produce dissimilar steel components that can be more cost-effective and time-efficient and allow for complex geometries to be made. A dissimilar steel system consisting of 410 martensitic stainless steel and AWS ER70S-6 mild steel is proposed to make hot stamps, making them more cost-efficient. However, the material interface's mechanical behavior in 410SS-mild steel additively manufactured material systems is not well understood. This …
Development Of A Wireless Telemetry Load And Displacement Sensor For Orthopaedic Applications, William Anderson
Development Of A Wireless Telemetry Load And Displacement Sensor For Orthopaedic Applications, William Anderson
Electronic Thesis and Dissertation Repository
Due to sensor size and supporting circuitry, in vivo load and deformation measurements are currently restricted to applications within larger orthopaedic implants. The objective of this thesis is to repurpose a commercially available low-power, miniature, wireless, telemetric, tire-pressure sensor (FXTH87) to measure load and deformation for future use in biomechanical applications. The capacitive transducer membrane of the FXTH87 was modified, and a relationship was reported between applied compressive deformation and sensor signal value. The sensor package was embedded within a deformable enclosure to illustrate potential applications of the sensor for monitoring load. Finite element analysis was an effective tool to …
Tailoring Texture, Microstructure, And Shape Memory Behavior Of Niti Alloys Fabricated By L-Pbf-Am, Sayed Ehsan Saghaian N.E.
Tailoring Texture, Microstructure, And Shape Memory Behavior Of Niti Alloys Fabricated By L-Pbf-Am, Sayed Ehsan Saghaian N.E.
Theses and Dissertations--Mechanical Engineering
Laser Powder Bed Fusion (L-PBF) is one of the most promising Additive Manufacturing (AM) methods to fabricate near net-shape metallic materials for a wide range of applications such as patient-specific medical devices, functionally graded materials, and complex structures. NiTi shape memory alloys (SMAs) are of great interest due to a combination of unique features, such as superelasticity, shape memory effect, high ductility, work output, corrosion resistance, and biocompatibility that could be employed in many applications in automotive, aerospace, and biomedical industries. Due to the difficulties with traditional machining and forming of NiTi components, the ability to fabricate complex parts, tailor …
Comparison Of Additively Manufactured And Wrought 17-4 Ph Stainless Steels In Ultra Low Cycle Fatigue, Timothy Strasser
Comparison Of Additively Manufactured And Wrought 17-4 Ph Stainless Steels In Ultra Low Cycle Fatigue, Timothy Strasser
Graduate Theses and Dissertations
Additive manufacturing (AM) processes allow for creation of complex geometries that are otherwise impractical to fabricate with traditional subtractive methods. AM technology has potential to improve the optimization of seismic lateral force resisting components which dissipate seismic energy through large plastic strains; however, the ultra low-cycle fatigue performance of AM metals are not yet well understood. Void formation during the AM fabrication process has potential to affect performance. This study compares the performance of heat-treated and non-heat-treated AM and wrought 17-4PH stainless steel in Ultra Low Cycle Fatigue. To understand ULCF performance differences between the AM and wrought specimens, post …
Investigation Of Multiple Torch Paw-Based Additive Manufacturing, Nathan Huft
Investigation Of Multiple Torch Paw-Based Additive Manufacturing, Nathan Huft
Graduate Theses & Non-Theses
PAW Print 3D (PP3D), a wire and arc additive manufacturing (AM) system was developed. PP3D comprises three plasma arc welding torches arranged radially around a central wire feed. Using three torches was hypothesized to eliminate sensitivity to travel direction. Two deposition modes were developed – continuous, which deposited continuous beads, and dabber, which deposited discreet “dabs” of material. Dabber was hypothesized to provide favorable solidification conditions that would refine the as-deposited grain structure. Three sets of process parameters for each deposition mode were developed. Ineffective workpiece melting was observed and investigated during process development. Using COMSOL Multiphysics software and experimental …
Manufacture Of Fused Deposition Modeling Joints Using Ultem 9085, Zane A. Willburn
Manufacture Of Fused Deposition Modeling Joints Using Ultem 9085, Zane A. Willburn
Theses and Dissertations
The manufacture of joints between a base structure and a structure manufactured via Fused Deposition Modeling (FDM) will be investigated. ULTEM 9085, a high temperature plastic with potential aerospace applications, will be the material used. The specific application this research is focused on is a robotic and mobile FDM printer capable of building structures onto other structures in space. A joint will be formed by fusing the base layer of the printed structure and the top of the base structure together. Tensile testing will be performed to determine the strength of the bond between parts. Tensile specimens will be manufactured …
Direct Write 3d Printing Of Functional Ceramics, Jorge Angel Diaz
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 …
Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose
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 …
Design Rules For Additive Manufacturing – Understanding The Fundamental Thermal Phenomena To Reduce Scrap, M. Reza Yavari, Kevin D. Cole, Prahalada K. Rao
Design Rules For Additive Manufacturing – Understanding The Fundamental Thermal Phenomena To Reduce Scrap, M. Reza Yavari, Kevin D. Cole, Prahalada K. Rao
Department of Mechanical and Materials Engineering: Faculty Publications
The goal of this work is to predict the effect of part geometry and process parameters on the direction and magnitude of heat flow heat flux in parts made using metal additive manufacturing (AM) processes. As a step towards this goal, the objective of this paper is to develop and apply the mathematical concept of heat diffusion over graphs to approximate the heat flux in metal AM parts as a function of their geometry. This objective is consequential to overcome the poor process consistency and part quality in AM. Currently, part build failure rates in metal AM often exceed 20%, …
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
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 …
Additive Manufacturing With High Density Polyethylene: Mechanical Properties Evaluation, Calvin Wampol
Additive Manufacturing With High Density Polyethylene: Mechanical Properties Evaluation, Calvin Wampol
Electronic Theses and Dissertations
High-density polyethylene is a common recyclable plastic that has a large potential as an additive manufacturing material due its economic and environmental benefits. However, high-density polyethylene has undesirable thermal properties that cause the material to shirk and not adhere to the printing bed during an additive manufacturing processes. Researchers have attempted to combat these thermal properties but have only created novel filaments of high-density polyethylene without being able to create 3D printed specimens for mechanical property testing. This paper presents several methods to create 3D printed specimens with pure high-density polyethylene filament on a fused filament fabrication type 3D printer. …
Microstructural Characterization Of LensTm Ti-6al-4v: Investigating The Effects Of Process Variables Across Multiple Deposit Geometries, Laura Christine Davidson
Microstructural Characterization Of LensTm Ti-6al-4v: Investigating The Effects Of Process Variables Across Multiple Deposit Geometries, Laura Christine Davidson
Browse all Theses and Dissertations
Laser based additive manufacturing of Ti-6Al-4V components is under consideration for aerospace applications. The mechanical properties of the finished components depend on their microstructure. Process mapping compares process variables such as heat source power, heat source travel speed, material feed rate, part preheat temperature and feature geometry to process outcomes such as microstructure, melt pool geometry and residual stresses. In this work, the microstructure of two-dimensional pads, multilayer pads, thin walls, and structural components at the steady state location was observed. A method for measuring β grain widths that allows for the calculation of standard deviations, confidence intervals, and variances …
Comprehensive Finite Element Modeling Of Ti-6al-4v Cellular Solids Fabricated By Electron Beam Melting, Edel Arrieta
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 …
Effects Of Fabrication Conditions On Mechanical Properties Of Ti-6al-4v Fabricated By Powder Bed Fusion Additive Manufacturing, Paola Azani
Open Access Theses & Dissertations
At the writing of this Thesis, additive manufacturing (AM) also known as 3D printing, has been popularized for its diversity in applications ranging from home and personal use, medical, industrial, consumer products, aerospace, architecture, automotive, military, fashion, food, art and more. Industries taking advantage of the design freedom and complexity offered by AM have exploded the growth of the technologies. Specifically, technologies that process metals using electron and laser beams have been recognized by the aerospace industry as a promising avenue for re-engineered components leading to reduced weight and improved engineering efficiencies for components like engine brackets and nozzles. However, …
Reducing Metal Alloy Powder Costs For Use In Powder Bed Fusion Additive Manufacturing: Improving The Economics For Production, Fransisco Medina
Reducing Metal Alloy Powder Costs For Use In Powder Bed Fusion Additive Manufacturing: Improving The Economics For Production, Fransisco Medina
Open Access Theses & Dissertations
Titanium and its associated alloys have been used in industry for over 50 years and have become more popular in the recent decades. Titanium has been most successful in areas where the high strength to weight ratio provides an advantage over aluminum and steels. Other advantages of titanium include biocompatibility and corrosion resistance. Electron Beam Melting (EBM) is an additive manufacturing (AM) technology that has been successfully applied in the manufacturing of titanium components for the aerospace and medical industry with equivalent or better mechanical properties as parts fabricated via more traditional casting and machining methods. As the demand for …
The Influence Of Build Parameters On The Microstructure During Electron Beam Melting Of Ti6al4v, Karina Puebla
The Influence Of Build Parameters On The Microstructure During Electron Beam Melting Of Ti6al4v, Karina Puebla
Open Access Theses & Dissertations
With the demand of devices to replace or improve areas, such as: electronic, biomedical and aerospace industries. Improvements in these areas of engineering have been in need due to the customer’s needs for product properties requirements. The design of components must exhibit better material properties (mechanical or biocompatible) close to those of any given product. Rapid prototyping (RP) technologies that were originally designed to build prototypes may now be required to build functional end-use products. To carry out the transition, from RP to rapid manufacturing (RM), the available materials utilized in RP must provide the performance required for RM. The …
Microstructural Architecture Developed In The Fabrication Of Solid And Open-Cellular Copper Components By Additive Manufacturing Using Electron Beam Melting, Diana Alejandra Ramirez
Microstructural Architecture Developed In The Fabrication Of Solid And Open-Cellular Copper Components By Additive Manufacturing Using Electron Beam Melting, Diana Alejandra Ramirez
Open Access Theses & Dissertations
The fabrication of Cu components were first built by additive manufacturing using electron beam melting (EBM) from low-purity, atomized Cu powder containing a high density of Cu2O precipitates leading to a novel example of precipitate-dislocation architecture. These microstructures exhibit cell-like arrays (1-3µm) in the horizontal reference plane perpendicular to the build direction with columnar-like arrays extending from ~12 to >60 µm in length and corresponding spatial dimensions of 1-3 µm. These observations were observed by the use of optical metallography, and scanning and transmission electron microscopy. The hardness measurements were taken both on the atomized powder and the Cu components. …