Mechanical Engineering Commons^™

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 …

Engineering Viscoelastic Behavior Of Carbon Fiber Reinforced Polymer Composites With Nanoparticles For Controlling Deployment Of Aerospace Structures, Mark Scherbarth

Mechanical Engineering ETDs

The United States Air Force is focused on reducing mass and power consumption of spacecraft to increase their capabilities for space missions. Low mass and power consumption can be achieved by using composites with low density and high stiffness and utilizing few satellite components. One way to achieve reduced mass is by eliminating attendant deployment mechanisms consuming valuable power and mass allocations on spacecraft with deployable structures. Secondary systems are typically used to assist deployable space structures to ensure 100% success. A passively deployed space structure would be of great value to the Department of Defense and the commercial marketplace. …

Optimization Of The Hot Embossing Parameters And Sintering Characterization For Alumina/Berea Sandstone Sintering, Justin F. Robbins

LSU Master's Theses

The purpose of this study is to investigate the process of hot embossing on alumina based ceramics as a cost-efficient procedure for manufacturing microfluidic testing components. Alumina ceramics were used as an exploratory phase for the final objective of the project, manufacturing of Berea sandstone based ceramic samples. Previous research has shown potential in using hot embossing on Alumina based ceramics; however, complications with extrusion and micro-structure quality were observed. For this reason, the research performed aimed to produce Berea Sandstone based components by first improving upon the embossing quality of alumina ceramics.

The thesis first investigates changes in the …

Design And Testing Of A Top Mask Projection Ceramic Stereolithography System For Ceramic Part Manufacturing, Dylan Robert De Caussin

Master's Theses

Ceramic manufacturing is an expensive process with long lead times between

the initial design and final manufactured part. This limits the use of ceramic as a viable material unless there is a large project budget or high production volume associated with the part. Ceramic stereolithography is an alternative to producing low cost parts through the mixing of a photo curable resin and ceramic particles. This is an additive manufacturing process in which each layer is built upon the previous to produce a green body that can be sintered for a fully dense ceramic part.

This thesis introduces a new approach …

Fabrication And Characterization Of Miniaturized Components Based On Extruded Ceramic-Filled Polymer Blends, Khurshida Sharmin

LSU Doctoral Dissertations

The objective of this work is to develop an improved manufacturing process for microstructured ceramic components that is based on co-extrusion. Co-extrusion of structured feedrods holds promise for development of multi-layered, functionally graded and/or textured structures. However, it requires a polymer binder that is difficult to remove before structures can be sintered to full density. A two-step debinding is introduced to eliminate debinding defects that are commonly observed in thermal debinding (TD). Cracking is a major issue due to a lack of pore spaces for outgassing of pyrolysis products in traditional TD. In two-step debinding, a soluble binder is removed …

Surface Modification Of Aluminum Alloys By Plasma Electrolytic Oxidation, Vahid Dehnavi

Electronic Thesis and Dissertation Repository

Plasma Electrolytic Oxidation (PEO) is a surface treatment for the production of ceramic oxide coatings with great properties, such as high wear and corrosion resistance, on metal substrates, particularly aluminum and magnesium alloys. Formation of PEO coatings involves complex processes and mechanisms that are difficult to study. Currently, the PEO process is in a transition phase from research to commercial application, with a primary focus on the corrosion and wear protection of light alloys, and has recently generated interest as a promising surface treatment for biomedical applications.

To justify the industrial application of PEO, a more systematic and in-depth study …

Atomistic Simulation And Virtual Diffraction Characterization Of Alumina Interfaces: Evaluating Structure And Stability For Predictive Physical Vapor Deposition Models, Shawn Patrick Coleman

Graduate Theses and Dissertations

The objectives of this work are to investigate the structure and energetic stability of different alumina (Al₂O₃) phases using atomistic simulation and virtual diffraction characterization. To meet these objectives, this research performs molecular statics and molecular dynamics simulations employing the reactive force-field (ReaxFF) potential to model bulk, interface, and surface structures in the θ-, γ-, κ-, and α-Al₂O₃ system. Simulations throughout this study are characterized using a new virtual diffraction algorithm, developed and implemented for this work, that creates both selected area electron diffraction (SAED) and x-ray diffraction (XRD) line profiles without assuming …

Low Strain Rate Studies Of Alumina Epoxy Composites Using Piezospectroscopy, Ashley Jones

Electronic Theses and Dissertations

Particulate composites are widely used in many aerospace and military applications as energetic materials, armor materials or coatings and their behavior under dynamic loads have gained increasing significance. The addition of modifiers such as alumina nanoparticles generally facilitates the improvement of the mechanical strength to density ratio due to high specific area and particle rigidity. This allows for sufficient particlematrix bonding and therefore improved stiffness and load transfer in the composite. Photo-luminescent α-alumina nanoparticles when embedded in an epoxy matrix allow for the added benefit of in situ measurements at low strain rates to provide stress-sensitive information using the particle …

Pool Boiling Enhancement Via Micro Ratchets, Lance Austin Brumfield

LSU Master's Theses

Nucleate boiling is an attractive method for achieving high heat flux at low superheat temperatures. It is frequently used for industrial applications such as heat exchangers and is being considered to cool advanced central processing units (CPU) which produce heat fluxes on the order of 1 MW/m2 and are becoming increasing less efficient to cool via forced conduction of air. The issues with implementing nucleate boiling as a cooling mechanism lies in the difficulty of quantifying the complex and numerous mechanisms which control the process. A comprehensive nucleate boiling model has yet to be formulated and will required in order …

The Design And Modification Of A Sputter System For Dc Reactive Sputtering Of Alumina And Zirconia Thin Films, Diane Van Ho

LSU Master's Theses

Yttria-stabilized zirconia (7% YSZ) is the most used material for thermal barrier coatings (TBCs) to reduce the conductive heat transfer on turbine blades, but it is not resistant to infrared radiation. In order to reduce radiation heat transfer, alternating materials, such as alumina and zirconia, can be used to fabricate multi-layer coatings in which each layer is optimized to reflect a targeted range of wavelength. This research aims to fabricate these multi-layer coatings by reactive magnetron sputtering. Reactive magnetron sputtering is the sputtering of an elemental target in the presence of a reactive gas that will react with the target …