Understanding the Influence of Process Parameters on the Mechanical Properties of Alumina Formed Through Lithography-Based Additive Manufacturing
Sarah is a PhD student in the Materials Science program at Colorado School of Mines. Her research involves studying lithography-based additive manufacturing of ceramic materials. Sarah is involved with the Colorado Center for Advanced Ceramics where she is a lab manager. In May 2017, Sarah completed her B.S. in Materials Science with a Geology minor at the University of Wisconsin – Eau Claire. She has previous research experience investigating the mechanical properties of superconducting ceramic materials. In her spare time, she enjoys the Colorado outdoors through skiing and climbing. She has her American Institute for Avalanche Research and Education Level 1 certification. She boulders and lead climbs outside with the goal of branching into trad climbing.
Of the various emerging solid freeform fabrication avenues for creating ceramics with intricate geometries, vat polymerization has emerged as a leading technique. Lithography-based ceramic manufacturing (LCM) enables the high-resolution fabrication of relatively large-sized parts in reasonable print times. LCM 3D printers use digital light processing to cure a photopolymeric ceramic slurry layer-by-layer to create a green body. LCM-formed parts, however, are susceptible to issues including delamination, bubble formation, cleaning damage, and agglomerates. The mechanical properties of parts made through this layered manufacturing technique are not well characterized as the impact of processing defects inherent to LCM processing has yet to be fully investigated. This study will employ alumina as the material to explore the impact of process parameters on defect generation in this printing technique. There is a wealth of data about the mechanical performance of traditionally processed alumina allowing for effective comparison with the performance of additively manufactured parts. Using Weibull analysis and fractography, this work will provide needed insight into the strength variability and critical flaw population of LCM-formed alumina. Parts with complex geometries will be analyzed to check if the strength-controlling flaws found in simple bars are also found in larger, more complex parts. The knowledge generated in this study will help establish more fundamental connections between processing conditions and part properties for the LCM ceramic forming technique. The work completed here will provide insight into whether traditional ceramic testing standards are effective for ceramic additive manufacturing or if new standards or conditions should be implemented.