Silicon carbide coatings for tri-isotropic (TRISO)-coated fuel particles were fabricated using a chemical vapor deposition process at different deposition temperatures. An internal pressurization mechanical testing method, devised to measure the strength of the silicon carbide coatings, was investigated. An enhanced strength equation was derived using finite element analysis and verified by an experimental method utilizing a soda-lime glass standard specimen. The strength and Weibull modulus of the silicon carbide were measured using the internal pressurization technique. The effect of the microstructure and deposition temperature on the strength of the silicon carbide coating is discussed. Finally the reliability of silicon carbide coatings for tri-isotropic-coated fuel particles was discussed in terms of the coating strength with a correlation of the effective surface area and Weibull statistics.

Keywords: Silicon carbide, Coating, Chemical vapor deposition, TRISO, Strength, Internal pressurization, Weibull statistics.