The microstructure and texture of Gilsocarbon graphite

Abstract

The material properties of nuclear graphite are defined by the as-manufactured graphite texture and their evolution due to irradiation and oxidation in reactors. Thus an understanding of the graphite microstructure and texture is essential in simulating and the predicting material property changes in nuclear graphite. The texture of nuclear graphite involves the preferred orientation of graphite crystallites and the domain structure. This study developed a technique based on combined micro-Raman spectroscopy mapping and atomic force microscope, and demonstrate the application of this technique to texture characterization of GCMB Gilsocarbon graphite. A crystallite orientation analysis approach was proposed to describe the local arrangement of graphite crystallites. For comparison, the texture characterization results are present for Gilsonite coke filler, and different parts of binder phase, respectively. The domain orientation within Gilsonite coke filler is irregular, but statistically follows the spherical particles. The major binder phase shows less ordered texture, however, certain parts of the binder phase shows very ordered planar crystallite orientation, and even larger lateral crystal size than that of filler particle. The clear description of texture provides the bases for future simulations and investigation of the properties and irradiation performance of Gilsocarbon graphite.