Effects of Microstructure on the Oxidation Behavior of A3 Matrix-Grade Graphite

Abstract

The oxidation behavior of matrix-grade graphite in air- or steam-ingress accident scenarios is of great interest for high-temperature gas reactors (HTGRs). In this study, the microstructures of two variants of matrix-grade graphite based on the German A3-3 and A3-27 formulations were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy, and correlated to oxidation behavior observed through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Through TEM imaging and selected area electron diffraction (SAED), a higher volume fraction of partially graphitized carbon was identified in the A3-3 type graphite than in the A3-27 type. This structure is believed to have contributed to the accelerated oxidation exhibited by A3-3 in the chemical reaction-controlled oxidation regime.

Department(s)

Materials Science and Engineering

Research Center/Lab(s)

Intelligent Systems Center

Comments

U.S. Department of Energy, Grant NRC 31310018M0044

Keywords and Phrases

Matrix Graphite; Microstructure; Oxidation; TEM; TGA/DSC

International Standard Serial Number (ISSN)

0002-7820; 1551-2916

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2021 American Ceramic Society, All rights reserved.

Publication Date

01 Jan 2021

Link to Full Text

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