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Additive manufacturing

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Articles 211 - 240 of 577

Full-Text Articles in Engineering

Predicting Defects In Laser Powder Bed Fusion Using In-Situ Thermal Imaging Data And Machine Learning, Sina Malakpour Estalaki, Cody S. Lough, Robert G. Landers, Edward C. Kinzel, Tengfei Luo Oct 2022

Predicting Defects In Laser Powder Bed Fusion Using In-Situ Thermal Imaging Data And Machine Learning, Sina Malakpour Estalaki, Cody S. Lough, Robert G. Landers, Edward C. Kinzel, Tengfei Luo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Variation in the local thermal history during the Laser Powder Bed Fusion (LPBF) process in Additive Manufacturing (AM) can cause micropore defects, which add to the uncertainty of the mechanical properties (e.g., fatigue life, tensile strength) of the built materials. In-situ sensing has been proposed for monitoring the AM process to minimize defects, but successful minimization requires establishing a quantitative relationship between the sensing data and the porosity, which is particularly challenging with a large number of variables (e.g., laser speed, power, scan path, powder property). Physics-based modeling can simulate such an in-situ sensing-porosity relationship, but it is computationally costly. …

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Hardware Security For Wireless Communications Systems Using Antenna-Based Radio Frequency Fingerprint Engineering, Noemi Miguelez Gomez Oct 2022

Hardware Security For Wireless Communications Systems Using Antenna-Based Radio Frequency Fingerprint Engineering, Noemi Miguelez Gomez

Doctoral Dissertations and Master's Theses

The design and application of novel physical-layer security techniques have been increasing in the last decades as means to enhance the security that more traditional techniques provide to wireless communications systems. Well-known hardware security techniques, such as radio frequency fingerprinting, use unintended manufacturing process variations and unique hardware structures in the semiconductors for applications such as identification and classification of the source of different transmitted signals, and detection of hardware modifications. The uniqueness of the features that two different modules present, even maintaining the same design, can be used for modules characterization at a lower cost and complexity than other …

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Thermal Post-Processing Of 3d Printed Polypropylene Parts For Vacuum Systems, Pierce Mayville, Aliaksei L. Petsiuk, Joshua M. Pearce Sep 2022

Thermal Post-Processing Of 3d Printed Polypropylene Parts For Vacuum Systems, Pierce Mayville, Aliaksei L. Petsiuk, Joshua M. Pearce

Michigan Tech Publications, Part 1

Access to vacuum systems is limited because of economic costs. A rapidly growing approach to reduce the costs of scientific equipment is to combine open-source hardware methods with digital distributed manufacturing with 3D printers. Although high-end 3D printers can manufacture vacuum components, again, the cost of access to tooling is economically prohibitive. Low-cost material extrusion 3D printing with plastic overcomes the cost issue, but two problems arise when attempting to use plastic in or as part of vacuum systems: the outgassing of polymers and their sealing. To overcome these challenges, this study explores the potential of using post-processing heat treatments …

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Influence Of Nano-Sized Sic On The Laser Powder Bed Fusion Of Molybdenum, Nathan E. Ellsworth, Ryan A. Kemnitz, Cayla C. Eckley, Brianna M. Sexton, Cynthia T. Bowers, Joshua R. Machacek, Larry W. Burggraf Sep 2022

Influence Of Nano-Sized Sic On The Laser Powder Bed Fusion Of Molybdenum, Nathan E. Ellsworth, Ryan A. Kemnitz, Cayla C. Eckley, Brianna M. Sexton, Cynthia T. Bowers, Joshua R. Machacek, Larry W. Burggraf

Faculty Publications

Consolidation of pure molybdenum through laser powder bed fusion and other additive manufacturing techniques is complicated by a high melting temperature, thermal conductivity and ductile-to-brittle transition temperature. Nano-sized SiC particles (0.1 wt%) were homogeneously mixed with molybdenum powder and the printing characteristics, chemical composition, microstructure, mechanical properties were compared to pure molybdenum for scan speeds of 100, 200, 400, and 800 mm/s. The addition of SiC improved the optically determined density and flexural strength at 400 mm/s by 92% and 80%, respectively. The oxygen content was reduced by an average of 52% over the four scan speeds analyzed. Two mechanisms …

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Automated Posture Positioning For High Precision 3d Scanning Of A Freeform Design Using Bayesian Optimization, Zhaohui Geng, Bopaya Bidanda Sep 2022

Automated Posture Positioning For High Precision 3d Scanning Of A Freeform Design Using Bayesian Optimization, Zhaohui Geng, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications

Three-dimensional scanning is widely used for the dimension measurements of physical objects with freeform designs. The output point cloud is flexible enough to provide a detailed geometric description for these objects. However, geometric accuracy and precision are still debatable for this scanning process. Uncertainties are ubiquitous in geometric measurement due to many physical factors. One potential factor is the object’s posture in the scanning region. The posture of target positioning on the scanning platform could influence the normal of the scanning points, which could further affect the measurement variances. This paper first investigates the geometric and spatial factors that could …

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Finite Fatigue Life Prediction Of Additively Manufactured Aircraft Engine Turbine Blade With Respect To Internal Defect Size And Location, Daniel G. Miller Sep 2022

Finite Fatigue Life Prediction Of Additively Manufactured Aircraft Engine Turbine Blade With Respect To Internal Defect Size And Location, Daniel G. Miller

Theses and Dissertations

Current fatigue life modeling techniques with respect to defects emphasize the dependence on the defect size with respect to fatigue life, but does not account for the effects of where a defect might be located. This research outlines a process to include defect location into the model analysis for a more precise prediction of the number of cycles to failure and where the finial failure could occur within a component. The focus is on a turbine blade structure using IN718 subjected to a pure vibratory load. The basic model predicts component life using a stress map from the frequency analysis …

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Additive Manufacturing Of Molybdenum For High Temperature Structural Applications, Megan L. Bustin Sep 2022

Additive Manufacturing Of Molybdenum For High Temperature Structural Applications, Megan L. Bustin

Theses and Dissertations

This research considered additive manufactured (AM) molybdenum (Mo) and the effect of three variables on microstructure, mechanical properties, and the relationship between the two. Test temperature, laser speed, and shield gas or build atmosphere were varied, and samples tested and analyzed using a three-point bending test, chemical composition, and optical and scanning electron microscopy. The relationship among variables and results using a Design of Experiments was limited compared to the inclusion of every tested sample. Most effects were expected: samples tested at room temperature were brittle without statistical significance; increasing laser speed resulted in decreased ductility and strain, smaller grain …

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Mechanical Properties And Tension-Tension Fatigue Behavior Of A Novel Additively Manufactured Polymer Matrix Composite At Room And Elevated Temperature, Grayson M. Harber Sep 2022

Mechanical Properties And Tension-Tension Fatigue Behavior Of A Novel Additively Manufactured Polymer Matrix Composite At Room And Elevated Temperature, Grayson M. Harber

Theses and Dissertations

The tension-tension fatigue behavior of a novel additively manufactured AM carbon fiber reinforced polymer matrix composite was studied. This novel material system consists of T1100 carbon fibers, and a UV photocured resin developed by Continuous Composites and Sartomer. Tensile properties and tension-tension fatigue were investigated for the 090 fiber orientation as well as for the ±45 fiber orientation. Specimens with 0/90 fiber orientation were tested at ambient laboratory temperature 23 °C and at elevated temperature 150 °C, while the specimens with the ±45 fiber orientation were tested only at ambient laboratory temperature. Tension-tension fatigue testing was carried out with a …

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Ultrafast Laser Ablation Of Inconel 718 For Surface Improvement, Sampson Canacoo, Enrique Contreras Lopez, Oscar Coronel, Farid Ahmed, Jianzhi Li, Anil K. Srivastava Sep 2022

Ultrafast Laser Ablation Of Inconel 718 For Surface Improvement, Sampson Canacoo, Enrique Contreras Lopez, Oscar Coronel, Farid Ahmed, Jianzhi Li, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications

Inconel 718 is considered difficult to machine because of its ability to maintain its properties at high temperatures. The low thermal conductivity of the alloy causes accelerated tool deterioration when machining. Selective laser melting (SLM) additive manufacturing introduces a possibility of eliminating these difficulties, and producing complex shapes with this difficult-to-machine material. However, high surface roughness and porosity usually occur at the surface of components produced through additive manufacturing. In this study, the surfaces of Inconel 718 samples produced through selective laser melting were treated using laser ablation. The process parameters for the laser ablation process were analyzed in …

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Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant Sep 2022

Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

Extrusion-based 3D printing with rapidly hardening polymeric materials is capable of building almost any conceivable structure. However, concrete, one of the most widely used materials for large-scale structural components, is generally based on inorganic binder materials like Portland cement. Unlike polymeric materials, a lack of precise control of the extent and rate of solidification of cement-based suspensions is a major issue that affects the ability to 3D-print geometrically complex structures. Here, we demonstrate a novel method for controllable-rapid solidification of concentrated mineral suspensions that contain a polymer binder system based on epoxy and thiol precursors as well as one or …

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Optimizing Build Plate Adhesion Of Polymers In Fused Granule Fabrication Processes, Alex Schroeder, Jason Weaver Aug 2022

Optimizing Build Plate Adhesion Of Polymers In Fused Granule Fabrication Processes, Alex Schroeder, Jason Weaver

Faculty Publications

Perhaps the most crucial element of fused granule fabrication (FGF) is material adhesion; in order to achieve a successful product, the material being printed must adhere to the build plate. For optimal products, the material should only adhere to the build plate until the print is complete, then be easily removable. This paper examines the effects of different build plates, environments, and bonding agents on material adhesion during the FGF process in a CNC mill machine. The force to remove polycarbonate (PC) and polypropylene (PP) from build plates was tested with various bonding agents. Except in one case, the adhesive …

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A Comparison Of Layer Deposition And Open Molding Of Petg By Fused Pellet Fabrication In An Additive Manufacturing System, Alex Gibson, Jason Weaver Aug 2022

A Comparison Of Layer Deposition And Open Molding Of Petg By Fused Pellet Fabrication In An Additive Manufacturing System, Alex Gibson, Jason Weaver

Faculty Publications

Additive manufacturing continues to offer new possibilities in both production and economics. The industry has quickly adopted it to rapidly produce parts that would be difficult or cost preventative otherwise. Recent innovation has expanded its capabilities, however there are still significant limitations. Most AM processes are restricted by materials available, in producing large parts, or by not achieving material deposition speeds to make certain products feasible. In addition, tight tolerances for features and surfaces cannot be produced without substantial post processing. High-speed Fused Pellet Fabrication (FPF) in combination with Hybrid Manufacturing (HM) offers expanded capabilities as additive and subtractive process …

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Waste Plastic Direct Extrusion Hangprinter, Aliaksei Petsiuk, Bharath Lavu, Rachel Dick, Joshua M. Pearce Aug 2022

Waste Plastic Direct Extrusion Hangprinter, Aliaksei Petsiuk, Bharath Lavu, Rachel Dick, Joshua M. Pearce

Michigan Tech Publications, Part 1

As the additive manufacturing industry grows, it is compounding the global plastic waste problem. Distributed recycling and additive manufacturing (DRAM) offers an economic solution to this challenge, but it has been relegated to either small-volume 3D printers (limiting waste recycling throughput) or expensive industrial machines (limiting accessibility and lateral scaling). To overcome these challenges, this paper provides proof-of-concept for a novel, open-source hybrid 3D printer that combines a low-cost hanging printer design with a compression-screw-based end-effector that allows for the direct extrusion of recycled plastic waste in large expandable printing volumes. Mechanical testing of the resultant prints from 100% waste …

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The Temperature Dependent Mechanical Response Of M250 Maraging Steel And Its Implications On Wire Arc Additive Manufacturing, Frank M. Brinkley Iii Aug 2022

The Temperature Dependent Mechanical Response Of M250 Maraging Steel And Its Implications On Wire Arc Additive Manufacturing, Frank M. Brinkley Iii

Theses and Dissertations

Wire-arc additive manufacturing (WAAM) is becoming increasingly common for large scale additive manufacturing (AM) applications because of its high deposition rate (2-3 kg/hr.). The rapid temperature changes and subsequent evolution of mechanical properties during AM can lead to large distortion and residual stresses. Finite element modeling of the AM process shows promise to minimize part distortion and residual stresses through improved path planning and process parameter optimization. However, accurate material properties of M250 before and after heat treatment are needed to properly characterize the property evolution from annealed to AM, to aged. Due to limited data on annealed M250, this …

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Ferrous Alloy Manufacturing For The Martian Surface Through In-Situ Resource Utilization With Ionic Liquids Harvested Iron And Bosch Process Carbon, Blake C. Stewart Aug 2022

Ferrous Alloy Manufacturing For The Martian Surface Through In-Situ Resource Utilization With Ionic Liquids Harvested Iron And Bosch Process Carbon, Blake C. Stewart

Theses and Dissertations

As research continues for the habitation of the Lunar and Martian surfaces, the need for materials for construction of structural parts, mechanical components, and tools remains as a major milestone. The use of in-situ resource utilization (ISRU) techniques is critical due to the financial, physical, and logistical burdens of sending supplies beyond low-Earth orbit. The Bosch process is currently in development as a life support system at the National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) to regenerate oxygen (O2) from metabolic carbon dioxide (CO2) with the byproduct of elemental carbon (C). The Bosch process presents a …

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Flow And Thermal Transport In Additively Manufactured Metal Lattices Based On Novel Unit-Cell Topologies, Inderjot Kaur Aug 2022

Flow And Thermal Transport In Additively Manufactured Metal Lattices Based On Novel Unit-Cell Topologies, Inderjot Kaur

Theses and Dissertations

The emergence of metal Additive Manufacturing (AM) over the last two decades has opened venues to mitigate the challenges associated with stochastic open-cell metal foams manufactured through the traditional foaming process. Regular lattices with user-defined unit cell topologies have been reported to exhibit better mechanical properties in comparison to metal foams which extend their applicability to multifunctional heat exchangers subjected to both thermal and mechanical loads. The current study aims at investigating the thermal-hydraulic characteristics of promising novel unit cell topologies realizable through AM technologies. Experimental investigation was conducted on four different topologies, viz (a) Octet, (b) Face-diagonal (FD) cube, …

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Out-Of-Plane Load-Bearing And Mechanical Energy Absorption Properties Of Flexible Density-Graded Tpu Honeycombs, Ibnaj Anamika Anni, Kazi Zahir Uddin, Nicholas Pagliocca, Nand Singh, Oyindamola Rahman, George Youssef, Behrad Koohbor Aug 2022

Out-Of-Plane Load-Bearing And Mechanical Energy Absorption Properties Of Flexible Density-Graded Tpu Honeycombs, Ibnaj Anamika Anni, Kazi Zahir Uddin, Nicholas Pagliocca, Nand Singh, Oyindamola Rahman, George Youssef, Behrad Koohbor

Henry M. Rowan College of Engineering Departmental Research

Honeycomb structures are widely used in applications that require excellent strain energy mitigation at low structural weights. The load-bearing and energy absorption capacity of honeycomb structures strongly depend on their cell wall thickness to edge ratios. This work studies the mechanical response and strain energy absorption characteristics of hexagonal honeycomb structures with various cell wall thicknesses in response to out-of-plane loading conditions. Honeycomb structures with various nominal densities are first additively manufactured from flexible thermoplastic polyurethane (TPU). A comprehensive experimental study characterized the mechanical strength, energy absorption performance, and the strain recoverability of the structures. Density-graded structures are then fabricated …

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Characterization Of Fatigue Strength Of Additively Manufactured Ti-6al-4v With Recoater Blade Interference Flaws And Residual Stresses Towards An Enhanced Fatigue Substantiation Methodology For Aerospace Structures Applications, Joshua Manyara Mochache Aug 2022

Characterization Of Fatigue Strength Of Additively Manufactured Ti-6al-4v With Recoater Blade Interference Flaws And Residual Stresses Towards An Enhanced Fatigue Substantiation Methodology For Aerospace Structures Applications, Joshua Manyara Mochache

Mechanical and Aerospace Engineering Dissertations - Archive

This research characterized the fatigue strength of additively manufactured (AM) Ti-6Al-4V, through fatigue and static tests conducted using specimens with and without recoater blade interference flaws (RBIF), and thus further enhanced the fatigue substantiation methodology for AM parts by using combined fatigue strength knock-down-factors (KDF) developed from this study. Qualification and certification (Q&C) of metallic AM parts, through acceptable methods for fatigue and damage tolerance (F&DT) substantiation, is an area where significant gaps still exist. While progress has been made in design as well as materials and process standardization, Q&C of additively manufactured metallic structural parts, especially those in civil …

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Characterization Of 3d Printed Parts Containing Integrated Functionality Via Ultrasonically Embedded Wires, David Abraham Sepulveda Aug 2022

Characterization Of 3d Printed Parts Containing Integrated Functionality Via Ultrasonically Embedded Wires, David Abraham Sepulveda

Open Access Theses & Dissertations

Material extrusion additive manufacturing has been widely adopted because it offers freedom of design, which allows complex geometry fabrication, and rapid prototyping. Interest in producing components with integrated functionality allowed forms of hybrid manufacturing to be developed such as the Multi3D system. This system produces parts with embedded components by combining additive, subtractive, soldering, dispensing, and embedding techniques. However, this involves pausing the printing process (which takes place in a controlled environment) and exposing it to ambient temperature where embedding takes places. In this research, the effect of embedding parts with 24 AWG copper for improved functionality was quantified mechanically. …

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Additive Manufacturing Of Aluminum Alloy By Metal Fused Filament Fabrication (Mf3)., Luke J. Malone Aug 2022

Additive Manufacturing Of Aluminum Alloy By Metal Fused Filament Fabrication (Mf3)., Luke J. Malone

Electronic Theses and Dissertations

This research studies metal-fused filament fabrication (MF3) for manufacturing aluminum alloy parts. An aluminum alloy powder-based feedstock with a polymer-binder system was extruded via capillary rheometry to form a filament. The filament was used to print green parts that were involved in a two-step debinding process combining solvent and thermal extraction of the polymer binder, then sintered in a partial vacuum. Resulting grain structure, sintered density, and mechanical properties will be characterized and compared to metal injection molded (MIM) specimens. The main objective is to gain an understanding of the MF3 process characteristics and the ensuing material properties and microstructure …

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Development Of A Custom, 3d-Printed, Multi-Microphone, Noise-Cancelling, Hearing Protection Device With A Magnetically Attached Printed Ear Canal For Sound Localization Preservation, Brenda Leticia Valadez Mesta Aug 2022

Development Of A Custom, 3d-Printed, Multi-Microphone, Noise-Cancelling, Hearing Protection Device With A Magnetically Attached Printed Ear Canal For Sound Localization Preservation, Brenda Leticia Valadez Mesta

Open Access Theses & Dissertations

Hearing loss is a prominent health issue that affects a significant fraction of the global population. One of the main causes behind hearing loss is exposure to harmful noise levels in the workplace. There have been multiple efforts to prevent hearing loss from excessive noise in occupational settings, such as hearing conservation programs and use of hearing protection devices (HPDs), however, these are often ineffective. Although HPDs are frequently available in the workspace, they are not used as intended since they usually generate discomfort and hindered sound localization. The loss of sound localization can be hazardous in occupational settings, since …

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Solution Synthesis And Additive Manufacturing Of Bismuth Telluride Nanoflakes For Flexible Energy Harvesting, Ariel E. Weltner Aug 2022

Solution Synthesis And Additive Manufacturing Of Bismuth Telluride Nanoflakes For Flexible Energy Harvesting, Ariel E. Weltner

Boise State University Theses and Dissertations

Flexible thermoelectric generators (TEGs) are energy harvesting devices which convert temperature differences into electrical power. These devices require no moving parts and offer silent and autonomous operation. The variety of suitable materials covering a broad range of operating temperatures positions TEGs as a promising renewable energy source using waste heat recovery, especially for space and microgravity applications. Conventional manufacturing of flexible electronic and thermoelectric devices requires complicated and relatively expensive processing, which limits the capabilities of in-space manufacturing. Additive manufacturing (AM) expands the use of flexible electronics to new surfaces, applications, and recently, low gravity conditions. Plasma jet printing (PJP) …

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Fabrication And Testing Of Catalyst-Infused Filament For 3d Printing Of Ignition-Augmented Hybrid Rocket Fuels, Kurt C. Olsen Aug 2022

Fabrication And Testing Of Catalyst-Infused Filament For 3d Printing Of Ignition-Augmented Hybrid Rocket Fuels, Kurt C. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis describes and addresses the need for reliable ignition in small satellite hybrid propulsion systems using higher density oxidizers. It describes methods of creating custom 3D printing ABS plastic based filaments that contain small amounts of catalysts. These catalysts lead to a more reliable and energy-efficient ignition of a hybrid rocked propulsion system using catalyst-infused ABS and nitrous oxide and oxygen blend called Nytrox, commonly known as ”laughing gas.” The ”laughing gas” has a higher density and can therefore provide more ”miles per gallon” in a hybrid propulsion system on a small satellite when compared to gaseous oxygen (GOX). …

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Flow In Additively Manufactured Super-Rough Channels, Samuel Altland, Xiaowei Zhu, Stephen Mcclain, Robert Kunz, Xiang Yang Jul 2022

Flow In Additively Manufactured Super-Rough Channels, Samuel Altland, Xiaowei Zhu, Stephen Mcclain, Robert Kunz, Xiang Yang

Mechanical and Materials Engineering Faculty Publications and Presentations

Metal additive manufacturing has enabled geometrically complex internal cooling channels for turbine and heat exchanger applications, but the process gives rise to large-scale roughness whose size is comparable to the channel height (which is 500 μm). These super-rough channels pose previously unseen challenges for experimental measurements, data interpretation and roughness modelling. First, it is not clear if measurements at a particular streamwise and spanwise location still provide accurate representation of the mean (time- and plane-averaged) flow. Second, we do not know if the logarithmic layer survives. Third, it is unknown how well previously developed rough-wall models work for these large-scale …

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Influence Of Aluminum Addition On The Laser Powder Bed Fusion Of Copper-Aluminum Mixtures, Nada Kraiem, Loic Constantin, A. Mao, Fei Wang, Bai Cui, Jean-François Silvain, Yongfeng Lu Jul 2022

Influence Of Aluminum Addition On The Laser Powder Bed Fusion Of Copper-Aluminum Mixtures, Nada Kraiem, Loic Constantin, A. Mao, Fei Wang, Bai Cui, Jean-François Silvain, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

The high optical reflectivity of copper (Cu) in the near infrared (NIR) domain and its elevated heat dissipation make Cu a challenging metal for laser powder bed fusion (LPBF), even with high energy densities (EDs). In this study, we demonstrated that adding aluminum (Al) powder by as little as 0.75, 1.5, and 3 wt.% substantially enhances Cu processability, leading to denser (up to 98%) and smoother (Ra = 3.3 𝜇m) Cu-Al parts as compared to 95% and 18 𝜇m, respectively, for the parts printed using pure Cu. In addition, this method reduces the ED required by a factor of two …

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In-Situ Infrared Thermographic Inspection For Local Powder Layer Thickness Measurement In Laser Powder Bed Fusion, Tao Liu, Cody S. Lough, Hossein Sehhat, Yi Ming Ren, Panagiotis D. Christofides, Edward C. Kinzel, Ming-Chuan Leu Jul 2022

In-Situ Infrared Thermographic Inspection For Local Powder Layer Thickness Measurement In Laser Powder Bed Fusion, Tao Liu, Cody S. Lough, Hossein Sehhat, Yi Ming Ren, Panagiotis D. Christofides, Edward C. Kinzel, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The laser powder bed fusion (LPBF) process is strongly influenced by the characteristics of the powder layer, including its thickness and thermal transport properties. This paper investigates in-situ characterization of the powder layer using thermographic inspection. A thermal camera monitors the temperature history of the powder surface immediately after a layer of new powder is deposited by the recoating system. During this process, thermal energy diffuses from the underlying solid part, eventually raising the temperature of the above powder layer. Guided by 1D modeling of this heat-up process, experiments show how the parameterized thermal history can be correlated with powder …

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Experimental Characterization Of Additively Manufactured Multi-Feather Wingtip Devices, Patricio Garzon Jul 2022

Experimental Characterization Of Additively Manufactured Multi-Feather Wingtip Devices, Patricio Garzon

Doctoral Dissertations and Master's Theses

Soaring birds have evolved to fly for long periods of time without flapping their wings. Inspired by the flight of these birds, the proposed thesis presents an experimental investigation focused on wingtip devices designed based on biomimicry. The overarching engineering objective was to reduce the induced drag as a means to improve the fuel efficiency via these experimental wingtips. An associated secondary objective was to establish a method for manufacturing complex structures suitable for wing tunnel testing. A manufacturing technique that involved using composite weaves to reinforce additively manufactured structures was developed. This technique has the potential to reduce manufacturing …

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Controlled Pre-Wetting Of Spread Powder And Its Effects On Part Formation And Printing Parameters In Binder Jetting Additive Manufacturing, Colton G. Inkley Jun 2022

Controlled Pre-Wetting Of Spread Powder And Its Effects On Part Formation And Printing Parameters In Binder Jetting Additive Manufacturing, Colton G. Inkley

Theses and Dissertations

Binder jetting is an additive manufacturing process that layer by layer builds a 3D model by selectively binding regions of powder using binder deposited though an inkjet printhead. The process offers several advantages over other additive manufacturing processes including fast build rates, vast material selection, decreased cost, and part resolution. The main disadvantage of binder jetting is poor mechanical properties, stemming from a poor understanding of the process physics. Porosity in final parts is not uncommon, but there is little understanding of where the porosity originates. The purpose of this thesis is to report the investigation of increased powder bed …

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Effect Of Additively Manufactured Padding On The Mechanical And Thermal Comfort Of Mtb-Backpacks, Frank I. Michel, Stefanie Zelt, Dominik Krumm, Andreas Knöchel, Stefan Schwanitz Jun 2022

Effect Of Additively Manufactured Padding On The Mechanical And Thermal Comfort Of Mtb-Backpacks, Frank I. Michel, Stefanie Zelt, Dominik Krumm, Andreas Knöchel, Stefan Schwanitz

International Sports Engineering Association – Engineering of Sport

No abstract provided.

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Performance Study Of Post-Processed Additively Manufactured Low Thrust Nozzles, Tyler W. Gerhold Jun 2022

Performance Study Of Post-Processed Additively Manufactured Low Thrust Nozzles, Tyler W. Gerhold

Theses and Dissertations

This research explores metal post-processing techniques to effectively reduce the large anomalous protrusions found in small additively manufactured low thrust rocket nozzles. Research has found that nozzles of this kind can experience losses in thrust of over 40%. Analytic theory of adiabatic nozzle flow with viscous losses for additively manufactured nozzles does not align with what has been found when tested experimentally. Compressible flow losses, such as shock wave formation inside the nozzle diverging cone, are likely the leading causes of such loss. Reduction in nozzle irregularities can likely yield results seen in analytic theory with similar performance to traditional …

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