Fabrication and metrology of SiC cladding and seals for containment and heat transfer applications

Abstract

Background SiC is a candidate material for high-temperature nuclear applications due to its high corrosion resistance, thermomechanical strength, and low neutron cross-section. Traditional manufacturing methods include sintering to a near-net shape with post-sinter finish machining. Methods Analysis of the metrology from fabricated SiC casings was conducted. SiC was fabricated using spark plasma sintering (SPS) under constant temperature and pressure (~2,000K; ~10MPa). Samples were then sandblasted to remove excess graphite and underwent metrological evaluation. Results Metrology indicates that dimensions may not be sufficiently predictable for net-shape fabrications. The process of mass dosing, human input, and sinter-forging lead to standard deviations of up to ~7%, suggesting that alternative tooling approaches are required to decrease the amount, and subsequent cost, of post-sinter machining. Dimensional compatibility trials using surrogate pellets show that machining is required. Conclusions The consequences of poor tolerances are discussed with respect to theoretical applications. This is an expected outcome for a ceramic fabrication process.