Mechanical Engineering Commons^™

Cmas/Volcanic Ash Infiltration Performance Of Yttria Rich-Zirconia Thermal Barrier Coatings Produced By Electron Beam Physical Vapor Deposition, Juan Jose Gomez Chavez

Open Access Theses & Dissertations

For many years the use of thermal barrier coatings (TBC) in gas turbine engines has allowed a significant increase in engine operating temperatures which are above the Ni-based super alloys' melting point. The base material for TBCs is the state of the art 7 wt % yttria stabilized zirconia (YSZ) which provides the thermal protection. Current industry demands for increased engine efficiency has pushed TBCs to the limits where significant technological constrains have been identified. One of the main ones represents the high temperature corrosion of the TBC material due to the ingestion of silicate based airborne particles commonly referred …

Compressive And Rheological Deformation Analysis Of Large Area Pellet-Fed Material Extrusion 3d Printed Parts In Relation To In Situ Thermal Imaging, Eduardo Meraz Trejo

Open Access Theses & Dissertations

In large area pellet extrusion additive manufacturing, the temperature of the substrate just prior to the deposition of a new subsequent layer has an effect on the overall structure of the part. Warping and cracking occur if the substrate temperature is below a specific threshold, but also deformation and deposition adhesion failure occur if the substrate temperature is above a certain threshold just prior to deposition of a new layer. Currently, Big Area Additive Manufacturing (BAAM) machine users mitigate this problem by trial and error, which is costly and may result in decreased mechanical properties, monetary losses and time inefficiencies. …

Tailoring The Mechanical And Optical Properties Of Silicon-Niobium-Nitride Composite Coatings, Cristian Orozco

Open Access Theses & Dissertations

Nitride nanocomposite thin films have generated significant attention as a result of their robust mechanical properties, excellent triobology, and good chemical (corrosion) stability. Due to their excellent hardness and high wear resistance NbN coatings have found use in a wide variety of applications such as the coating of cutting tools and to strengthen the surface mechanical properties of superconducting cavities. The mechanical properties of NbN can be further improved through mixing with Si3N4, leading to the formation of a nanocomposite structure. NbN-Si3N4 nanocomposite coatings have been actively studied due to their high hardness, high elastic modulus, and high resistance to …

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

Open Access Theses & Dissertations

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

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

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

Open Access Theses & Dissertations

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

Thermal Characterization Of Abs/Carbon Fiber, Abs/ Glass Fiber And Petg/Glass Fiber Reinforced Composites Used In Large Area Additive Manufacturing, Fernando Adrian Rodriguez Lorenzana

Open Access Theses & Dissertations

Additive manufacturing has seen continuous advancements, such as the inclusion of large-area additive manufacturing extrusion systems. These systems precede small-scale 3D printing by means of research and technological development for the manufacturing of plastic and fiber industries. Big Area Additive Manufacturing (BAAM), a material extrusion process, is capable of 3D printing large parts using thermoplastic composites by adding fiber reinforcements. The incorporation of fibrous materials, carbon fiber (CF) or glass fiber (GF), is a common practice in which percentage nominal ratios of fiber reinforcement by weight are implemented to the polymer matrix. In general, this enables warpage reduction during printing, …

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

Open Access Theses & Dissertations

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

Cradle To Grave Lifecycle Process Analysis For Transuranic Waste Management Los Alamos National Laboratory, Cesar Enrique Dominguez

Open Access Theses & Dissertations

Amid World War II, in the late 1930s, nuclear fission was discovered. This revolution gave way to the development of nuclear technologies, including the world's first atomic bomb; these advancements in nuclear research left behind radioactive waste. Radioactive waste is known as the byproduct of nuclear reactors, fuel processing plants, hospitals, nuclear research facilities, as well as the result from the decommissioning and dismantling of radiation-exposed buildings and materials. This byproduct may be dangerous to workers, the public, and the environment and must, therefore, be handled with utmost safety. Given this, radioactive waste must be processed, stored, and disposed of …

A Modified Wilshire Model For Creep Deformation And Damage Prediction, Jaime Aaron Cano

Open Access Theses & Dissertations

In this work, a new constitutive model, the WCS model, is derived that combines the Wilshire equations with continuum damage mechanics (CDM) for the long-term prediction of creep deformation, damage, and rupture. Long-term creep data is expensive and time-consuming to obtain because conventional creep testing is real-time. There is a need to extrapolate long-term creep behaviors from short-term data. Models that can accurately predict long-term creep behavior over a wide range of boundary conditions are vital for design engineers. The classic Wilshire equations can accurately extrapolate the long-term stress-rupture, minimum-creep-strain-rate, and time-to-strain of various alloys as their functional form has …

Structures And Daq System For The Lox/Lch4 500 And 2000 Lbf. Rocket Engines, Rachel Pilgrim

Open Access Theses & Dissertations

With the progression of space exploration and research, new alternative fuels and fuel combinations have been discovered. The ability to produce methane from Mars' atmosphere and oxygen from Mars' regolith has led to the two becoming a great alternative propellant combination for rocket propulsion systems. To further advance LOX/LCH4 propulsion systems, a 500 and 2000 lbf rocket engine were designed and manufactured and are to be launched from the MIRO cSETR Technology Research and Innovation Acceleration Park (tRIAc) in Fabens, Texas for data collection and analysis. The objective of this thesis is to give a thorough overview of the static …

Development And Environmental Testing Of A Single-Axis Printer Inside A 1u Cubesat For On-Orbit Servicing Repairs In Low Earth Orbit, Perla Rocio Perez

Open Access Theses & Dissertations

As additive manufacturing is becoming an established technology in space, new emerging strategies improve the efficiency of the printing processes. Orbital Factory 2 (OF-2) is a small satellite-or CubeSat-developed at the University of Texas at El Paso (UTEP) which launched to space on November 2019. In January 2020, it will be released in low earth orbit (LEO). OF-2 is a 1U (10x10x10cm) CubeSat that carries a one-axis printer experiment as its primary payload. This printer was developed and tested in-house. The experiment focuses on printing electrically conductive ink on a printing circuit board that verifies the conductivity on the trace …

Development Of An Iridium-Ceramic Substrate Catalyst Bed For The Decomposition Of Ionic Green Liquid Monopropellants, Alejandro Andre Vazquez

Open Access Theses & Dissertations

In an effort to advance green monopropellant propulsion using ionic liquids, the Center for Space Exploration and Technology Research (cSETR) has developed a pellet based catalyst bed for the decomposition of AF-M315E. The present paper will go over some of the fundamental research conducted towards the development of a catalyst bed and some of its applications. Three different catalyst bed designs were produced where each uses a different ceramic substrate material. The three different substrates are aluminum oxide, tungstated zirconia, silicon carbide each coated with iridium as the catalyst material. An experimental setup for testing the catalytic decomposition AF-M315E was …

Cfd Dem Analysis Of A Dry Powder Inhaler, Antara Badhan

Open Access Theses & Dissertations

Dry powder inhalers (DPIs), used as a means for pulmonary drug delivery, typically contains a combination of an Active Pharmaceutical Ingredient (API) and significantly larger carrier particles. The micro-sized drug particles - which have a strong propensity to aggregate and a poor aerosolization performance - are mixed with significantly large carrier particles that are unable to penetrate the mouth-throat region to deagglomerate and entrain the smaller API particles in the inhaled airflow. The performance of a DPI, therefore, depends on entrainment the carrier-API combination particles and the time and thoroughness of the deagglomeration of the individual API particles from the …

Numerical Investigation Of Molten Metal Infiltration And Pillared Cooling Systems At Microscale, Shaikh Tanveer Tanveer Hossain

Open Access Theses & Dissertations

Flow-through porous media at pore-scales is one of the less explored sides of fluid mechanics due to the complexity associated with highly irregular pore geometry. Most of the established methods that try to quantify such flow are based on statistical observations of flow through numerous porous specimens. Such understandings may satisfy the need for applications where micro-level details are not a concern. Some numerical approaches did try to analyze the micro-level flow, but the analysis was confined to small sample sizes due to the intensive computation challenge. There are several applications of porous media flow where analyzing the large-scale flow …

Additive Manufactured Ear Pinna For Spatial Cue Preservation In Custom Hearing Devices, Carlos Felipe Acosta Carrasco

Open Access Theses & Dissertations

Advancements in additive manufacturing/3D printing technologies has permitted the fabrication of intricate features such as the ones present in the human ear. The outer ear, also known as the pinna, allows for the spectral cues from incoming sound to be captured and identified. The hypothesis of the preservation of auditory localization and externalization relies on the fabrication of an ear pinna via additive manufacturing embedded into a headset for spectral cue preservation and hearing protection. Before exploring these custom circumaural hearing devices, a study on the fabrication process of AM pinnae was performed. The KEMAR system for acoustic research was …

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 …

Small Satellite Development At Utep, Emily Herzog

Open Access Theses & Dissertations

The small satellite industry has seen tremendous growth in recent years. A CubeSat is a particular type of standardized small satellite that follows the CubeSat specifications. These specifications define the structural, testing, and operational requirements of the satellite. This standard facilitates cheaper design, integration, and launch of satellites, allowing smaller organizations to participate in the normally costly area of space exploration.

The University of Texas at El Paso has recognized the opportunity and has begun developing several CubeSats. The two that are the topic of this Thesis are called Orbital Factory II (OFII) and Orbital Factory X (OFX). An on-orbit …

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

Open Access Theses & Dissertations

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

Pressureless Sintering Of Zirconium Diboride Obtained By Combustion Synthesis, Gabriel Llausas

Open Access Theses & Dissertations

Magnetohydrodynamic (MHD) direct power generation has the potential to significantly increase the thermal efficiency of coal fired power plants. Materials for MHD electrodes should have high melting points, high electrical and thermal conductivities, and excellent thermal shock and corrosion resistance. Zirconium diboride (ZrB2), which belongs to the class of ultra-high temperature ceramics (UHTC), is a promising material for this application. Mechanically activated self-propagating high-temperature synThesis (MASHS) is an attractive method for its fabrication. Previous studies have shown that zirconium diboride can be fabricated from inexpensive oxides of zirconium and boron (ZrO2 and B2O3) using magnesium as a reducing agent and …

Materials Characterization In The Development Of Combustion-Based Methods For Synthesis Of Niobium Silicides, Edgar Maguregui

Open Access Theses & Dissertations

The use of characterization techniques is essential for a better understanding of novel manufacturing processes and for investigating how the process parameters affect the products. Mechanically activated self-propagating high-temperature synthesis (MASHS) is an attractive method for the production of high-temperature structural materials. In the present work, it was used to fabricate Nb5Si3 compound and Nb5Si3/Nb composites. It has been shown that for mechanical activation of Nb/Si mixtures, a planetary ball mill is more effective than a shaker ball mill used in prior research on MASHS of Nb5Si3. The influence of mixture composition and experimental parameters, such as milling time and …

Development Of An Ionic Green Monopropellant 1 Newton Thruster For Small Satellite Application, Jaclyn Mona Mejia

Open Access Theses & Dissertations

In effort to advance green monopropellant propulsion using AF-M315E, a 1N thruster was developed to demonstrate the propellant capabilities for low thrust requirement missions. The current study presents the development of a 1 Newton thruster. The thruster was designed based on available literature for initial parameters. In house developed catalyst was packed into the 1 Newton thruster, and mounted onto a thrust stand for testing. Two configurations of catalyst were used for this testing campaign. As a result, temperature peaks from AF-M315E decomposition gases reached up to 1400°C with an iridium loading factor of 25% by mass with both catalyst …