Ultra-High Temperature Ceramics: Materials, Manufacturing, And Machine Development

This research aimed to advance the 3D printing of ultra-high-temperature ceramic matrix composites (UHTCMCs) and develop a custom Direct Ink Writing (DIW) system with multimaterial and in-line mixing capabilities. The study first focused on creating ZrB₂–SiC composites reinforced with aligned silicon carbide fibers (SiCf) using paste extrusion. By formulating suspensions with a preceramic polymer (SMP-10), ZrB₂, and SiCf, the study assessed how fiber alignment influenced key properties such as thermal and electrical conductivity and mechanical strength. Green curing and pyrolysis transformed the printed parts into UHTCMCs, with results showing substantial improvements in thermal conductivity—nearly double that of non-aligned parts—and a 10-fold increase in electrical conductivity when fibers were aligned. Despite the presence of pores that limited final conductivity, increased fiber content significantly enhanced fracture strength, suggesting that a fully dense, aligned composite could achieve even higher performance. The second focus of this research involved developing a custom DIW system to process yield-pseudoplastic ceramic inks. This system enables exploration of functional designs for composite ceramic armor and supports testing of biologically inspired armor structures, such as fish scales and abalone nacre. Future DIW system enhancements will include heating for viscosity control, adaptation for magnetically responsive inks, and UV curing capabilities. Overall, this research highlights the potential of tailored DIW-based additive manufacturing for creating UHTCMCs with optimized thermal, mechanical, and electrical properties, facilitating applications in high-speed and high-stress environments.