Doctoral Dissertations
Keywords and Phrases
Additive manufacturing; Carbon fiber reinforced composites; Continuous fiber reinforcement; High-speed 3D printing; Nanocomposites; Transparent ceramics
Abstract
"This research focused on developing fundamental knowledge of process-material interactions for additive manufacturing of multifunctional materials that are highly desirable in high-tech industries for potential weight and space savings. Multifunctional materials are very sensitive to defects, which severely hinder performance. Thus, defect formation was systematically studied to develop strategies and methodologies to efficiently fabricate high-performance materials and composites. Blown-powder-based laser additive manufacturing of transparent spinel ceramics was investigated to reduce porosity and cracking, defects that hindered transparency and mechanical properties. A systematic study of processing parameters revealed that laser power and powder flow rate had the largest effects on defect formation and inspired a novel vertical growth deposition method for fabrication of highly transparent ceramics. Second phase doping showed promise for thermal crack control. Due to differences in gas transport mechanisms, it was shown that filament-fed processes have significant advantages over powder-based methods for producing highly densified and transparent ceramics. A subsequent work focused on additive manufacturing of carbon fiber composites, another lightweight and high-performance material with multifunctionality potential. A novel 5-axis 3D printing approach mitigated damage to continuous fibers and enhanced high-speed additive manufacturing. Void formation due to poor impregnation of polymer matrix into fiber bundles was addressed with carbon nanotube coatings to promote resin wicking. Very high-strength continuous carbon fiber composites were fabricated by a stereolithography inspired method utilizing infiltration and compression to improve interlayer bonding"-- Abstract, p. iii
Advisor(s)
Dong, Xiangyang
Committee Member(s)
Okafor, A. Chukwujekwu (Anthony Chukwujekwu)
Kinzel, Edward C.
Liou, Frank W.
Watts, Jeremy Lee, 1980-
Leu, M. C. (Ming-Chuan)
Department(s)
Mechanical and Aerospace Engineering
Degree Name
Ph. D. in Mechanical Engineering
Publisher
Missouri University of Science and Technology
Publication Date
Spring 2025
Pagination
xix, 246 pages
Note about bibliography
Includes_bibliographical_references_(pages 242-244)
Rights
©2023 John Michael Pappas , All Rights Reserved
Document Type
Dissertation - Open Access
File Type
text
Language
English
Thesis Number
T 12486
Recommended Citation
Pappas, John Michael, "Additive Manufacturing of Multifunctional Materials and Composites" (2025). Doctoral Dissertations. 3385.
https://scholarsmine.mst.edu/doctoral_dissertations/3385
