Joining of SiC/SiC composite materials through preceramic polymers for nuclear fuel claddings

This thesis explores the use of Ceramic Matrix Composites (CMCs), specifically silicon carbide (SiC/SiC), for applications in high-stress environments such as nuclear energy production. The research focuses on an experimental approach to joining silicon carbide composite components using preceramic polymers, specifically polycarbosilanes, as a binding material. These polymers undergo a transformation from polymer to ceramic during a thermal process, including pyrolysis at temperatures up to 1500°C. Challenges associated with this method include material shrinkage during pyrolysis, porosity, and interface wettability, all of which impact the joint integrity. These challenges are addressed within the framework of the study, which aims to expand the functionality of advanced ceramics in complex geometries, thus enhancing their industrial applicability. By demonstrating the feasibility of such techniques for nuclear-grade components, this work contributes to the broader understanding of advanced ceramic applications in high-stress fields, promoting enhanced safety and efficiency. The findings are presented across five chapters, covering theoretical background, preceramic polymer properties, experimental procedures, results, and future implications.