Date of Award
2025-08-01
Degree Name
Master of Science
Department
Mechanical Engineering
Advisor(s)
Francisco Medina
Abstract
This thesis presents an experimental validation of a simplified extrusion model intended to predict dimensional accuracy in ceramic Direct-Ink Writing (DIW). Given the inherent complexity of ceramic paste formulations, extrusion processes, and shape retention during additive manufacturing, it is crucial to validate simplified models that can accurately forecast bead geometry and subsequent dimensional fidelity. A custom-designed force tester was developed to emulate ram extrusion conditions and determine key parameters using the Benbow-Bridgwater equation while attempting to be a low-cost alternative. This approach is meant for rapid, affordable assessment of ceramic paste extrusion characteristics without the need for complex rheological testing. The force tester fell short of expectations due to the number of tests necessary to acquire the paste characteristics of a single formulation. Single-line, single-layer, and multi-layer prints were produced and assessed using a laser profilometry scanning system. Bead and layer geometries were measured, evaluating the predictive accuracy of the simplified volumetric extrusion calculation typically employed in polymer extrusion slicers. Experimental results demonstrated that the simplified model accurately predicted bead width and height to within approximately 5-10% of targeted dimensions under stable extrusion conditions. Through these investigations, the study identified critical processing parameters that influence dimensional fidelity, including optimal nozzle dimensions, infill overlap and layer spacing. Additionally, the presence of extrusion defects such as bead discontinuities, pressure fluctuations, and liquid-phase migration were characterized and related directly to paste formulation and printing parameters.
Ultimately, this research confirms the practical utility of simplified extrusion models in ceramic DIW, highlighting their capabilities and limitations. The insights gained provide a solid foundation for future advancements in slicer development and extrusion control, aimed at enhancing the predictability, consistency, and dimensional accuracy of printed ceramic parts.
Language
en
Provenance
Received from ProQuest
Copyright Date
2025-08
File Size
86 p.
File Format
application/pdf
Rights Holder
Jason McCleary
Recommended Citation
McCleary, Jason, "Evaluating Extrusion Model Accuracy Using Laser Profilometry In Ceramic Robocasting Via Custom G-Code" (2025). Open Access Theses & Dissertations. 4409.
https://scholarworks.utep.edu/open_etd/4409