Optimization of fabrication routes for high-power titanium carbide targets and their characterization for ultra-high-temperature nuclear applications

This thesis investigates the fabrication and characterization of titanium carbide/carbon (TiC/C) targets for high-temperature nuclear applications, with particular reference to Isotope Separation On-Line (ISOL) systems. A particle-free photocurable sol--gel formulation was processed by Digital Light Processing (DLP) to produce monolithic and architected specimens, including bulk discs, gyroids, and random truss structures. The additively manufactured material ($TiC_{AM}$) was compared with a conventionally produced reference material ($TiC_{STD}$). The fabrication route included controlled drying, carbonization at $1450^{\circ}$C, and high-vacuum carbothermal reduction at $1750^{\circ}$C. Physical, structural, and chemical characterization showed a strong difference between the two materials. Nitrogen physisorption analysis confirmed higher surface specific area for $TiC_{AM}$ due to micro and meso porosity. XRD analysis confirmed the presence of crystalline TiC. TGA was performed to determine the carbon to titanium carbide ratio, highlighting higher value for $TiC_{AM}$. Intermediate analyses showed that the carbon-rich composition was already present after the $1450^{\circ}$C pre-treatment, while the investigated drying conditions, printer hardware, and exposure parameters did not show a systematic relationship with the final titanium content. Proton irradiation at 62~MeV and 1~$\mu$A for 5~min did not produce observable macroscopic cracking in the investigated specimens. Overall, DLP enabled the fabrication of highly porous and geometrically complex TiC/C structures, while control of the final Ti:C composition remains the main aspect requiring further optimization.