High-Temperature X-Ray Diffraction Study of Coating-Substrate Compatibility in Yttria-Coated Graphite

摘要

A high-temperature x-ray diffraction (XRD) study of the compatibility of yttria (Y sub 2 O sub 3 ) coatings on graphite substrates showed a near-surface reaction rate consistent with an autocatalytic model. The model was more appropriate for thicker coatings than for thin ones. The reaction product, yttrium carbide (YC sub 2 ), transformed from face-centered cubic to tetragonal during the reaction. The phase stability was dependent upon carbon stoichiometry. (ERA citation 10:013748)