Mechanical Engineering Commons^™

Performance Metrics For Powder Feeder Systems In Additive Manufacturing, Venkata Sivaram Bitragunta

Masters Theses

"In blown powder Direct Metal Deposition (DMD) process, parts are built by adding metal powder on the melt pool created by the laser system. At low feed rates powder feeder systems have perturbations. The study focused on relationship between the perturbation frequencies by inherent powder feeder designs and its impact on deposition quality. Performance metric determine the relation between perturbations in the powder flow and quality of the deposit. To determine performance metric, various powder feeder designs were analyzed. Perturbation frequencies were introduced to the disk feeder design. The quality of the deposit was determined by the surface roughness of …

Design And Development Of The Portable Build Platform And Heated Travel Envelope For The Multi3d Manufacturing System, Steven Daniel Ambriz

Open Access Theses & Dissertations

The final product functionality of parts produced by Additive Manufacturing (AM) can, in part, be improved by the inclusion of multi-material capabilities. The “Multi3D system” that is under development at The University of Texas at El Paso uses material extrusion printing (or fused deposition modeling), solid conductor wire embedding, direct-write, component placement, and micromaching to enable multi-material fabrication. The Multi3D was designed to transport a workpiece between manufacturing stations via a six-axis robot, portable build platform (PBP), and a controlled temperature environment or chamber that travels to each manufacturing station. The heated travel envelope (HTE) was included to mitigate thermal …

Fused Deposition Modeling (Fdm) Fabricated Part Behavior Under Tensile Stress, Thermal Cycling, And Fluid Pressure, Mohammad Shojib Hossain

Open Access Theses & Dissertations

Material extrusion based additive manufacturing (AM) technology, such as fused deposition modeling (FDM), is gaining popularity with the numerous 3D printers available worldwide. FDM technology is advancing from exclusively prototype construction to achieving production-grade quality. Today, FDM-fabricated parts are widely used in the aerospace industries, biomedical applications, and other industries that may require custom fabricated, low volume parts. These applications are and were possible because of the different production grade material options (e.g., acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyphenylsulfone (PPSF), etc.) available to use in FDM systems. Recent researchers are exploring other material options including polycaprolactone (PCL), polymethylmethacrylate (PMMA), …

Additive Manufacturing Laser Deposition Of Ti-6al-4v For Aerospace Repair Application, Nanda Kumar Dey

Masters Theses

"Parts or products machined from high performance metals are very expensive, partly due to the processing complexities during manufacturing. Therefore, many high performance metal parts users, such as the aerospace industry, mold/die casting industry, heavy machinery consumers etc., extend the service of these damaged parts by employing repair or remanufacturing technology. The research objective is to use laser deposition and machining processes to repair titanium parts.

This thesis discusses a new way of approach for developing a repair process for Ti-6Al-4V for the aerospace industry using Laser Metal Deposition (LMD). The repairs were conducted in a multi-axis hybrid manufacturing systems …

Characterization Of 304l Stainless Steel By Means Of Minimum Input Energy On The Selective Laser Melting Platform, Ben Brown

Masters Theses

"Developing parameter sets for new materials on the Selective Laser Melting (SLM) platform has traditionally been done through the use of single line processing windows and a basic design of experiments (DOE) which would include varying machine parameters to maximize density. This study expands the traditional method by determining the main effects statistically for density, allowing for a more in depth analysis wherein the experimental results are statistically correlated to the variable machine parameters used. With this analysis, parameter optimization with respect to achieving near full density, while also considering build rates, can be performed. New parameters for 304L stainless …

Numerical Analysis Of Thermal Stress And Deformation In Multi-Layer Laser Metal Deposition Process, Heng Liu

Masters Theses

"Direct metal deposition (DMD) has gained increasing attention in the area of rapid manufacturing and repair. It has demonstrated the ability to produce fully dense metal parts with complex internal structures that could not be achieved by traditional manufacturing methods. However, this process involves extremely high thermal gradients and heating and cooling rates, resulting in residual stresses and distortion, which may greatly affect the product integrity. The purpose of this thesis is to study the features of thermal stress and deformation involved in the DMD process. Utilizing commercial finite element analysis (FEA) software ABAQUS, a 3-D, sequentially coupled, thermo-mechanical model …

Parameter Optimization For Controlling Aluminum Loss When Laser Depositing Ti-6al-4v, Richard Charles Barclay

Masters Theses

"The ability to predict the mechanical properties of engineering materials is crucial to the manufacturing of advanced products. In the aerospace industry, Ti-6Al-4V is commonly used to build structures. Any deviation from the alloy's standard properties can prove detrimental. Thus, the compositional integrity of the material must be controlled. The ability to directly build and repair large, complicated structures directly from CAD files is highly sought after. Laser Metal Deposition (LMD) technology has the potential to deliver that ability. Before this process can gain widespread acceptance, however, a set of process parameters must be established that yield finished parts of …

Development Of A Thermal Imaging Feedback Control System In Electron Beam Melting, Emmanuel Rodriguez

Open Access Theses & Dissertations

The Electron Beam Melting (EBM) process is a promising technology in the rapid manufacturing of metal components. EBM has the potential to reduce the cost of metal parts by minimizing the use of raw materials and machining time. The EBM technology has several advantages over other additive manufacturing (AM) technologies of metal, such as manufacturing speed and mechanical properties of the finished parts. For the process to be accepted in the aerospace industry as a flight-ready manufacturing technology, however, improved control and feedback must be implemented in the building process for better part quality and uniform production in manufacturing. As …

Integration Of Ultrasonic Consolidation And Direct-Write To Fabricate An Embedded Electrical System Within A Metallic Enclosure, Ludwing A. Hernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A research project was undertaken to integrate Ultrasonic Consolitation (UC) and Direct-Write (DW) technologies into a single apparatus to fabricate embedded electrical systems within an ultrasonically consolidated metallic enclosure. Process and design guidelines were developed after performing fundamental research on the operational capabilities of the implemented system. In order to develop such guidelines, numerous tests were performed on both UC and DW. The results from those tests, as well as the design and process guidelines for the fabrication of an embedded touch switch, can be used as a base for future research and experimentation on the UC-DW apparatus. The successful …

Experimental Investigation Of Effect Of Environment Temperature On Freeze-Form Extrusion Fabrication, Xiyue Zhao, Michael S. Mason, Tieshu Huang, Ming-Chuan Leu, Robert G. Landers, Greg Hilmas, Samuel J. Easley, Michael W. Hayes

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing technique that extrudes ceramic loaded aqueous pastes layer by layer below the paste freezing temperature for component fabrication. A computer controlled 3-D gantry system has been developed for the FEF process. The system includes a temperature control subsystem that allows for fabrication of components below the paste freezing temperature. The low temperature environment allows for larger component fabrication. Comparisons in terms of layer thickness, self-sustaining ability, and system response were performed between 0⁰C and -20⁰C for alumina sample fabrications. The minimum deposition angles without use of support material have been determined for …