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Full-Text Articles in Engineering
Controlled Pre-Wetting Of Spread Powder And Its Effects On Part Formation And Printing Parameters In Binder Jetting Additive Manufacturing, Colton G. Inkley
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 …
Multi-Material 3d-Printed Silicone Vocal Fold Models, Clayton Adam Young
Multi-Material 3d-Printed Silicone Vocal Fold Models, Clayton Adam Young
Theses and Dissertations
Self-oscillating synthetic vocal fold (VF) models are often used to study human voice production. In this thesis, a method for fabricating multi-layer self-oscillating synthetic VF models using silicone 3D printing is presented. Multi-material 3D printing enables faster fabrication times with more complex geometries than traditional casting methods and builds a foundation for producing VF models with potentially more life-like geometries, materials, and vibratory characteristics. The printing method in this study used a custom dual extruder and slicing software to print UV-curable liquid silicone into a gel-like support matrix. The extruder was fabricated using high-torque stepper motors with high resolution leadscrews …
Optical Observation Of Large Area Projection Sintering, Derek Black
Optical Observation Of Large Area Projection Sintering, Derek Black
Theses and Dissertations
Polymer powder bed fusion (PBF/P) is one of many additive manufacturing (AM) processes utilized for producing polymer parts from digital 3D models. AM is preferred over traditional manufacturing methods in many applications due to advantages including tool-less manufacturing, high geometric complexity, short lead times, and reduced material waste. However, many industries that stand to benefit the most from AM are limited in their ability to use AM parts in large part due to low confidence in AM part quality. Among the polymer AM processes, PBF/P processes show significant promise for these applications due to their comparatively high isotropy and mechanical …
The Impact Of Inkjet Parameters And Environmental Conditions In Binder Jetting Additive Manufacturing, Trenton Miles Colton
The Impact Of Inkjet Parameters And Environmental Conditions In Binder Jetting Additive Manufacturing, Trenton Miles Colton
Theses and Dissertations
Binder jetting is an additive manufacturing process in which a part is fabricated layer-by-layer using inkjet technology to selectively dispense binder into powder layers in a designated area. The approach gives this process significant advantages over other additive manufacturing processes such as lower cost, capability to print in a wide range of materials, and little to no heat applied. Although binder jetting has many advantages and has been successful implemented in various industries its overall rate of adoption is slow compared to other processes. This is largely due to poor mechanical properties and consistency in printing which stems from a …
Active Thermography For Additive Manufacturing Processes, Nicholas Jay Wallace
Active Thermography For Additive Manufacturing Processes, Nicholas Jay Wallace
Theses and Dissertations
The goal of the research conducted for this master's thesis is to understand if active thermography is a suitable technique to detect (identify) and measure (approximate depth and or size) defects in additive manufacturing (AM) processes. Although other non-destructive measurement techniques exist, active thermography is an attractive option for AM applications because of the short measurement times that could be implemented between each layer of a print, and because of the relatively inexpensive equipment required. However, pulse thermography is typically applied to detect larger defects (>1 mm) in materials with high thermal conductivity. It was uncertain if active thermography …
Feasibility And Impact Of Liquid/Liquid-Encased Dopants As Method Of Composition Control In Laser Powder Bed Fusion, Taylor Matthew Davis
Feasibility And Impact Of Liquid/Liquid-Encased Dopants As Method Of Composition Control In Laser Powder Bed Fusion, Taylor Matthew Davis
Theses and Dissertations
Additive manufacturing (AM) – and laser powder bed fusion (LPBF) specifically – constructs geometry that would not be possible using standard manufacturing techniques. This geometric versatility allows integration of multiple components into a single part. While this practice can reduce weight and part count, there are also serious drawbacks. One is that the LPBF process can only build parts with a single material. This limitation generally results in over-designing some areas of the part to compensate for the compromise in material choice. Over-designing can lead to decreased functional efficiency, increased weight, etc. in LPBF parts. Methods to control the material …
Effects Of Conformal Cooling Channels On Additively Manufactured Injection Molding Tooling, Tyler Blaine Whatcott
Effects Of Conformal Cooling Channels On Additively Manufactured Injection Molding Tooling, Tyler Blaine Whatcott
Theses and Dissertations
This study focuses on the cycle-averaged mold temperature of additively manufactured injection molding tooling and how it is affected by conformal cooling channels. This was done by producing a benchmark mold out of Digital ABS produced by Stratasys, an acrylic based photopolymer, which was then used to produce injection molded parts until tool failure. Another, more cost-effective material, High Temp Resin produced by Formlabs, another acrylic based photopolymer, was also tested but yielded very little success. Then the mold design was altered by adding conformal cooling channels and again tested by producing injection molded parts while tracking the mold temperature. …
Silicone 3d Printing Processes For Fabricating Synthetic, Self-Oscillating Vocal Fold Models, Taylor Eugene Greenwood
Silicone 3d Printing Processes For Fabricating Synthetic, Self-Oscillating Vocal Fold Models, Taylor Eugene Greenwood
Theses and Dissertations
Synthetic, self-oscillating vocal fold (VF) models are physical models whose life-like vibration is induced and perpetuated by fluid flow. Self-oscillating VF models, which are often fabricated life-size from soft silicone elastomers, are used to study various aspects of voice biomechanics. Despite their many advantages, the development and use of self-oscillating VF models is limited by the casting process used to fabricate the models. Consequently, this thesis focuses on the development of 3D printing processes for fabricating silicone VF models. A literature review is first presented which describes three types of material extrusion 3D printing processes for silicone elastomers, namely direct …
Development And Analysis Of 3d-Printed Synthetic Vocal Fold Models, Ryan Gregory Romero
Development And Analysis Of 3d-Printed Synthetic Vocal Fold Models, Ryan Gregory Romero
Theses and Dissertations
Vocal fold models are valuable for studying voice production. They provide an alternative method of studying the mechanics of the voice that does not require in vivo experimentation or the use of excised human or animal tissue. In this thesis, a new method of creating vocal fold models through additive manufacturing is described. The purpose of this research was to reduce model fabrication time, to decrease the number of model failures during manufacturing, and to lay the foundation for creating models with more lifelike geometric and material properties. This research was conducted in four stages. First, a suitable silicone additive …
Crack Healing In 304l Stainless Steel Using Additive Manufacturing And Friction Stir Processing (Fsp), Cameron Scott Gygi
Crack Healing In 304l Stainless Steel Using Additive Manufacturing And Friction Stir Processing (Fsp), Cameron Scott Gygi
Theses and Dissertations
Continuing an investigation on using FSP to heal stress corrosion cracks (SCC) in welds on nuclear reactors, this study seeks to use AM in addition to FSP to aid crack repair. Previous studies address that current repair technology on nuclear reactors involves the use of TIG welding which can allow helium atoms to aggregate and form voids at the grain boundaries. This weakens the material and renders the repair ineffective. Another previous study evaluated the effectiveness of FSP alone in repairing SCC which did have defects depending on the parameters used during FSP. This study evaluated the use of AM …