Engineering Commons^™

Investigation Of 2195 And 2219 Post Weld Heat Treatments For Additive Friction Stir Lap Welds, Matthew Champagne

University of New Orleans Theses and Dissertations

To evaluate potential uses for friction stir welding in additive manufacturing, two separate parts were fabricated, one of 2195-T84 and the other 2219-T87, utilizing fixed pin techniques and additive lap welds. The parts were cut into samples, artificially aged and subjected to Rockwell hardness (HRB), Vickers hardness, micrographic photography, and metallographic imaging on both pre- and post- heat treatment. Additionally, tensile testing was performed on the heat-treated samples. A comparisons of test results showed a minimal increase in the yield strength of the 2195-T84 samples compared to as-welded tensile results obtained from a previous project. The ultimate tensile strength was …

Highly Vented Truss Wall Honeycomb Structures, David J. Sypeck

Publications

A vented honeycomb structure with a plurality of honey­comb cells arranged in a hierarchical order and having a plurality of truss walls, each truss wall including a plurality of members. The vented honeycomb structure is fabricated by joining a plurality of sheets of trusses using any one of an expansion, a corrugation, and a slotting process. Fabri­cation can also occur by deposition, casting, additive, extru­sion, or aligning and joining methods. The honeycomb cells, truss walls, truss wall openings, and truss wall members can be functionally graded.

The Vibe, Sarah P. Douglass

Capstones

The Vibe is a long-form narrative about where tech is taking the female orgasm. The piece concludes that physiological research is a required next step when creating the climax of the future.

http://sarahpdouglass.com

A Framework Towards Technology Creation In Africa: Focusing On Ghana, Martin Yao Donani, Hannatu Abue Kugblenu, Azindow Bawa Fuseini

International Journal of African Development

Underdevelopment in Africa has been historical and a global concern coupled with the quest for good governance. Several efforts have been made in academia, national governments, the international community, and other institutional arrangements to reverse the trend. These efforts however are yet to produce a lasting result as Africa is still characterized by low productivity output, poverty and a widening technology gap when compared to other developing regions of the world. Conventional approaches used to address the African problem have consistently been devoid of indigenous technology development. Technology is here seen as paramount to every form of production on which …

Real Time And High Fidelity Quadcopter Tracking System, Tyler Mckay Hall

Computer Engineering

This project was conceived as a desired to have an affordable, flexible and physically compact tracking system for high accuracy spatial and orientation tracking. Specifically, this implementation is focused on providing a low cost motion capture system for future research. It is a tool to enable the further creation of systems that would require the use of accurate placement of landing pads, payload acquires and delivery. This system will provide the quadcopter platform a coordinate system that can be used in addition to GPS.

Field research with quadcopter manufacturers, photographers, agriculture and research organizations were contact and interviewed for information …

Usa Boccia Ball Ramp For Athletes With Quadriplegia, Alissa A. Koukourikos, Matthew Lee, Nathan Bernards

Mechanical Engineering

In this report, the design process in creating an assistive device for Boccia Classification 3 (BC3) players is outlined. The initial research steps, including research into the rules of the game, capabilities of the players, and existing products is documented to show where ideas for the product stemmed from. This transitions into requirements that the sponsor requested, and preliminary designs and ideas for the product. Finally, this report explains the details of the final design, which has been analyzed for safety, ease of use, and ability to function under different conditions. The processes of manufacturing and testing will also be …

Dyno-Mite Redesign, Brandon Joseph Miller, Daniel Robert Hoffman, Richard Demedici Young

Mechanical Engineering

The Cal Poly Mechanical Control Systems Laboratory currently employs an outdated device, known as the Motomatic, to teach students about various motor characteristics and control methods. These include open-loop vs. closed-loop control, speed vs. position control, and DC motor response curves. The current device does not function properly and produces unreliable data due to overwhelming non-linear effects such as stiction and shaft misalignment. Our team was tasked with designing a replacement device that retains many of the same educational goals as the original lab procedure, while also adding new educational goals pertaining to the device system dynamics. The new apparatus, …

Friction Stir Welding Manufacturing Advancement By On-Line High Temperature Phased Array Ultrasonic Testing And Correlation Of Process Parameters To Joint Quality, Daniel James Huggett

LSU Doctoral Dissertations

Welding, a manufacturing process for joining, is widely employed in aerospace, aeronautical, maritime, nuclear, and automotive industries. Optimizing these techniques are paramount to continue the development of technologically advanced structures and vehicles. In this work, the manufacturing technique of friction stir welding (FSW) with aluminum alloy (AA) 2219-T87 is investigated to improve understanding of the process and advance manufacturing efficiency. AAs are widely employed in aerospace applications due to their notable strength and ductility. The extension of good strength and ductility to cryogenic temperatures make AAs suitable for rocket oxidizer and fuel tankage. AA-2219, a descendent of the original duralumin …

Distributed Manufacturing Of Flexible Products: Technical Feasibility And Economic Viability, Aubrey Woern, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Distributed manufacturing even at the household level is now well established with the combined use of open source designs and self-replicating rapid prototyper (RepRap) 3-D printers. Previous work has shown substantial economic consumer benefits for producing their own polymer products. Now flexible filaments are available at roughly 3-times the cost of more conventional 3-D printing materials. To provide some insight into the potential for flexible filament to be both technically feasible and economically viable for distributed digital manufacturing at the consumer level this study investigates 20 common flexible household products. The 3-D printed products were quantified by print time, electrical …

Application Of Surface Treatments To Improve Fuel Efficiency Of Internal Combustion Engines, Amirabbas Akbarzadeh

LSU Master's Theses

To improve the tribological performance of contacting surfaces, different surface modification methods can be employed. Surface texturing and surface coating are examples of viable techniques developed for this purpose. Surface texturing involves creating micropatterns on the contacting surfaces while surface coating requires depositing a thin layer of a suitable material on the surface(s) to improve the component’s friction and wear characteristics. The performance of textured surfaces is affected by the geometric characteristic of textures.When dealing with surface coating parameters, the parameters of interests are the type of coating materials and their thicknesses.

The current study aims to experimentally study the …

Note On The Rate And Energy Efficiency Limits For Additive Manufacturing, Timothy Gutowski, Sheng Jiang, Daniel Cooper, Gero Corman, Michael Hausmann, Jan-Anders Manson, Timo Schudeleit, Konrad Wegener, Matias Sabelle, Jorge Ramos-Grez, Dusan P. Sekulic

Mechanical Engineering Faculty Publications

We review the process rates and energy intensities of various additive processing technologies and focus on recent progress in improving these metrics for laser powder bed fusion processing of metals, and filament and pellet extrusion processing of polymers and composites. Over the last decade, observed progress in raw build rates has been quite substantial, with laser metal processes improving by about 1 order of magnitude, and polymer extrusion processes by more than 2 orders of magnitude. We develop simple heat transfer models that explain these improvements, point to other possible strategies for improvement, and highlight rate limits. We observe a …

Process Management And Design Layout Of High Throughput Screening, Anthony Vasquez, Kyle Dupuy

Industrial and Manufacturing Engineering

Calibr is a pharmaceutical company in San Diego and growing very quickly rate and need help redesigning their lab layout and in doing so reducing their cycle times and down times in machines. In addition to this, they do not currently have an accurate measurement of how long their processes take in an overall cycle. The objective of this project is to provide Calibr with a redesigned layout to accommodate new equipment as well as a software tool that can output Gantt charts for their planning of their testing. Our approach to this project first included mapping out the facilities …

Surface Topography Formation And Thermographic Analysis In Laser Polishing Of H13 Tool Steel, Joshua D. Miller

Electronic Thesis and Dissertation Repository

Laser polishing, in its simplest form, is the melting of a small layer of material via laser radiation. This creates a small molten pool which is re-distrusted across the surface, resulting in a much smoother finished surface. Although this process has been around for decades now, there has been a recent insurgence into industrial applications. Despite this, the phenomena that occur during the process are still not fully understood. Therefore, increasing the knowledge surrounding the process would be ideal.

To accomplish this, various input parameters of the process are altered to analyze the effect on the finished polished surface. Through …

Polar Exploration (University Focus) Research Into Smart Materials Continues At The University Of Dublin With The Development Of Methods To Record And Present Data To Demonstrate The Magnetorheological Effect When A Magnetic Field Is Applied To A Mr Elastomer Sample, Dave Gorman, Niall Murphy, Ray Ekins

Conference Papers

Research into methods to record and present data to demonstrate the Magnetorheological effect when a magnetic field is applied to a Magnetorheological Elastomer sample. By Dave Gorman, Niall Murphy and Ray Ekins, Technological University Dublin, Republic of Ireland A Magnetorheological Elastomer (MRE) is an example of a smart material as it undergoes a change in its physical properties when in the presece of an external magnetic field. This change in properties is known as the Magnetorheological (MR) effect and the manner in which it is achieved and reported, is of critical importance to the future development of MRE-based components. To …

3d Printing Of Functional Materials: Surface Technology And Structural Optimization, Dongxing Zhang

Electronic Thesis and Dissertation Repository

There has been a surge in interest of 3D printing technology in the recent 5 years with respect to the equipment and materials, because this technology allows one to create sophisticated and customized parts in a manner that is more efficient regarding both material and time consumption. However, 3D printing has not yet become a mainstream technology within the established manufacturing routes. One primary factor accounting for this slow progress is the lack of a broad variety of 3D printable materials, resulting in limited functions of 3D printed parts.

To bridge this gap, I present an integrated strategy to fabricate …

Open Source 3-D Printed Nutating Mixer, Dhwani K. Trivedi, Joshua M. Pearce

Department of Materials Science and Engineering Publications

As the open source development of additive manufacturing has led to low-cost desktop three-dimensional (3-D) printing, a number of scientists throughout the world have begun to share digital designs of free and open source scientific hardware. Open source scientific hardware enables custom experimentation, laboratory control, rapid upgrading, transparent maintenance, and lower costs in general. To aid in this trend, this study describes the development, design, assembly, and operation of a 3-D printable open source desktop nutating mixer, which provides a fixed 20° platform tilt angle for a gentle three-dimensional (gyrating) agitation of chemical or biological samples (e.g., DNA or blood …

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco

Libraries' Newsletters

No abstract provided.

Ultraprecise Single Point Inverted Cutting Of Right Triangular Prismatic Retroreflectors: Process Enhancements And Cutting Mechanics, Nicolas Milliken

Electronic Thesis and Dissertation Repository

Automotive lighting industry relies on retroreflective components to increase driver awareness in low-light conditions since their primary functionality is to return incident light back to the source and/or observer with minimal scatter.

Presently, industry makes use of conventional pin-bundling techniques for the fabrication of the retroreflective components. This method is time consuming, labour intensive, and restrictive with respect to the design process. For these reasons, the ultraprecise single point inverted cutting (USPIC) technology was developed as an efficient alternative for manufacturing novel right triangular prismatic (RTP) retroreflective structures.

This thesis outlines a number of enhancements that improve both the quality …

Additive Manufacturing Process Of 3d Polyaniline Transducers Via Direct Ink Writing, Frederick Benjamin Holness

Electronic Thesis and Dissertation Repository

Electroactive polymers exhibit a change in properties, typically size or shape, in response to electrical stimuli. One class of electroactive polymer of particular interest are the conjugated polymers, whose conjugated backbone structure imparts electrical conductivity. However, this structure imposes processing limitations restricting their form to 2D structures. To overcome this, we develop specially formulated polyaniline- based blends via counter-ion induced thermal doping for the fabrication of 3D conductive structures via direct ink writing. This approach employs multi-material extrusion for the production of structures with passive and active features, rapid device fabrication, and improved design freedom. A model of the thermal …

Pulsed Laser Beam Welding Of Pd43Cu27Ni10P20 Bulk Metallic Glass, Ling Shao, Amit Datye, Jiankang Huang, Jittisa Ketkaew, Sung Woo Sohn, Shaofan Zhao, Sujun Wu, Yuming Zhang, Udo D. Schwarz, Jan Schroers

Electrical and Computer Engineering Faculty Publications

We used pulsed laser beam welding method to join Pd₄₃Cu₂₇Ni₁₀P₂₀ (at.%) bulk metallic glass and characterized the properties of the joint. Fusion zone and heat-affected zone in the weld joint can be maintained completely amorphous as confirmed by X-ray diffraction and differential scanning calorimetry. No visible defects were observed in the weld joint. Nanoindentation and bend tests were carried out to determine the mechanical properties of the weld joint. Fusion zone and heat-affected zone exhibit very similar elastic moduli and hardness when compared to the base material, and the weld joint shows high …

Relating Processing Of Selective Laser Melted Structures To Their Material And Modal Properties, Nicholas E. Capps, James S. Urban, Brian M. West, Cody S. Lough, Adriane Repogle, Troy Hartwig, Ben Brown, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Selective Laser Melting (SLM) creates metal parts by fusing powder layer-by-layer. It provides significant design flexibility and the possibility of low-volume production. The engineering properties of the printed metal are a function of the local thermal history. This creates challenges for validating Additively Manufactured (AM) parts. This paper correlates the engineering properties (density, modulus, yield strength and ultimate strength) for tensile test specimens created with different process parameters with the resonant frequencies determined using modal testing. The paper shows that yield and ultimate strengths for these specimens can be determined using modal analysis.

Fiber-Fed Laser-Heated Process For Printing Transparent Glass, John M. Hostetler, Jonathan T. Goldstein, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents the Additive Manufacturing (AM) of glass using a fiber-fed process. Glass fiber with a diameter of 100 μm is fed into a laser generated melt pool. A CO₂ laser beam is focused on the intersection between the fiber and the work piece which is positioned on a four-axis computer controlled stage. The laser energy at λ=10.6 μm is directly absorbed by the silica and locally heats the glass above the working point. By carefully controlling the laser power, scan speed, and feed rate, bubble free shapes can be deposited including trusses and basic lenses. Issues unique …

Investigation Of Build Strategies For A Hybrid Manufacturing Process Progress On Ti-6al-4v, Lei Yan, Leon Hill, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The various processing parameters of a hybrid manufacturing process, including deposition and machining, is being investigated with a Design of Experiment (DoE). The intent was to explore the effect of different build strategies on the final part’s Vickers hardness, tensile test, fatigue life, and microstructure. From this experiment, the processing parameters can be linked to various mechanical properties. This will lead to the ability to create a combination of deposition and machining parameters, which will result in improved mechanical properties.

Development Of A Hybrid Manufacturing Process For Precision Metal Parts, Leon Hill, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper summarizes the research and development of a hybrid manufacturing process to produce fully dense metal parts with CNC-level precision. High performance metals, such as titanium alloys, nickel superalloys, tool steels, stainless steels, etc. can benefit from this process. Coupling the additive and the subtractive processes into a multi-axis workstation, the hybrid process, can produce and repair metal parts with accuracy. The surface quality of the final product is similar to the industrial milling capability. To achieve such a system, issues of the metal deposition process and the automated process planning of the hybrid manufacturing process will be discussed.

Review Of Am Simulation Validation Techniques, Aaron Flood, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Due to the complexity of Additive Manufacturing (AM), it can require many trial runs to obtain processing parameters which produce a quality build. Because of this trial and error process, the drive for simulations of AM has grown significantly. Simulations only become useful to researchers if it can be shown that they are true representations of the physical process being simulated. All simulations have different methods of validation to show that they are an accurate representations of the process. This paper explores the various methodologies for validation of laser based metal AM simulations, focusing mainly on the modeling of the …

Building Zr-Based Metallic Glass Part On Ti-6al-4v Substrate By Laser-Foil-Printing Additive Manufacturing, Yingqi Li, Yiyu Shen, Ming-Chuan Leu, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Through using Zr intermediate layers, Zr_52.5Ti₅Al₁₀Ni_14.6Cu_17.9 metallic glass (MG) parts are successfully built on Ti-6Al-4V substrates by laser-foil-printing (LFP) additive manufacturing technology in which MG foils are laser welded layer-by-layer onto the substrate. The printed MG part is free of porosity, cracking and crystallization; additionally, its glass transition temperature, crystallization temperature, micro-hardness, and tensile strength are very similar to the original MG material. The Zr intermediate layers are aimed at preventing direct interaction between the first layer of MG foil and the Ti substrate; otherwise, the welded MG foils would peel …

Mechanical Properties Of 304l Parts Made By Laser-Foil-Printing Technology, Chia-Hung Hung, Yiyu Shen, Ming-Chuan Leu, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser-Foil-Printing (LFP) is a novel laminated object manufacturing process for metal additive manufacturing. It fabricates three-dimensional metal parts by using a dual-laser system to weld and cut metal foils layer by layer. A main advantage of LFP is the higher cooling rate compared to powder-based laser additive manufacturing processes due to the thermal conductivity difference between foil and powder. This study focuses on the mechanical properties of 304L stainless steel parts built by the LFP process. The experimental results indicate that the yield strength and ultimate tensile strength of LFP fabricated 304L SS parts are higher by 9% and 8% …

Effect Of Optimizing Particle Size In Laser Metal Deposition With Blown Pre-Mixed Powders, Wei Li, Jingwei Zhang, Xinchang Zhang, Sreekar Karnati, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Functionally Graded Material (FGM) is often fabricated by Laser metal deposition with pre-mixed multiple powders (PMM-powder). Since the supplied PMM-powder directly affects FGM’s composition, investigation on PMM-powder’s property is greatly needed. This paper employed experimental method to observe an important problem: PMM-powder separation in fabricating FGM. A novel particle size optimization method was introduced as solution to eliminate the powder separation. Pre-mixed pure Cu and 4047 Al powders were used to do two experiments. The first experiment result disclosed the existence of powder separation. By optimizing the particle size, the PMM-powder separation was effectively solved in the second experiment result.

Thermal Modeling Of 304l Stainless Steel Selective Laser Melting, Lan Li, Cody S. Lough, Adriane Repogle, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper describes the continuum thermal modeling of the Selective Laser Melting (SLM) process for 304L stainless steel using Abaqus. Temperature dependent thermal properties are obtained from literature and incorporated into the model capturing the change from powder to fully dense stainless steel. The thermal model predicts the temperature history for multi-track scans under different process parameters (laser power, effective scanning speed, hatch spacing) which is used to extract the melt-pool size, solidification rate, and temperature gradients. These are compared to experimental results obtained from a Renishaw AM250 in terms of the melt pool size, grain structure, and cell spacing. …

Towards Defect Detection In Metal Slm Parts Using Modal Analysis "Fingerprinting", James Urban, Nick E. Capps, Brian M. West, Troy Hartwig, Ben Brown, Robert G. Landers, Douglas A. Bristow, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The validation of Additively Manufactured (AM) materials is a difficult and expensive process because the local engineering properties are a function of the thermal history. The thermal history varies with the process parameters, as well as the part geometry. This paper presents a case study using modal testing to identify defects in realistic AM parts. A setup consisting of a Scanning Laser Doppler Vibrometer (LDV) was used to identify the resonant frequencies for several geometrically identical parts on a build plate. Parts with suboptimal process parameters from purposely varying the process parameters, are identified by a shift in the mode …