Synthesis and Analysis of Alpha Silicon Carbide Components for Encapsulation of Fuel Rods and Pellets Available to Purchase

The chemical, mechanical and thermal properties of silicon carbide (SiC) along with its low neutron activation make it an attractive material for encapsulating fuel rods and fuel pellets. The alpha phase of SiC has particularly attractive thermal properties. Unfortunately, it requires very high temperature processing and continuous alpha SiC fiber is not available commercially. This paper describes a method for fabricating continuous, composite (SiC/C) fibers as well as monolithic SiC fibers by direct conversion of carbon fibers using SiO vapor at ∼ 1600°C. EDS analysis indicates the converted SiC product contains 1:1 stoichiometric amounts of C and Si. Hexagonal (α) SiC was found to be the dominant crystal structure by x-ray diffraction.