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Effects of microstructure on the oxidation behavior of A3 matrix‐grade graphite
Author(s) -
Bratten Adam,
Duan Jiaqi,
Hoffman Andrew,
Wen Haiming,
He Xiaoqing,
Stempien John D.
Publication year - 2021
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17468
Subject(s) - graphite , microstructure , thermogravimetric analysis , scanning electron microscope , differential scanning calorimetry , materials science , transmission electron microscopy , selected area diffraction , raman spectroscopy , chemical engineering , nuclear graphite , analytical chemistry (journal) , composite material , chemistry , nanotechnology , organic chemistry , thermodynamics , optics , physics , engineering
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.