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Title: Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air

In this paper, the oxidation rates of several nuclear-grade graphites, NBG-18, NBG-17, IG-110 and IG-11, were measured in air using thermogravimetry. Kinetic parameters and oxidation behavior for each grade were compared by coke type, filler grain size and microstructure. The thickness of the oxidized layer for each grade was determined by layer peeling and direct density measurements. The results for NBG-17 and IG-11 were compared with those available in the literature and our recently reported results for NBG-18 and IG-110 oxidation in air. The finer-grained graphites IG-110 and IG-11 were more oxidized than medium-grained NBG-18 and NBG-17 because of deeper oxidant penetration, higher porosity and higher probability of available active sites. Variation in experimental conditions also had a marked effect on the reported kinetic parameters by several studies. Finally, kinetic parameters such as activation energy and transition temperature were sensitive to air flow rates as well as sample size and geometry.
Authors:
ORCiD logo [1] ;  [2] ;  [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Univ. of Missouri, Columbia, MO (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 500; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Missouri, Columbia, MO (United States)
Sponsoring Org:
USDOE Office of Nuclear Energy (NE); Dept. of Education (United States)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
OSTI Identifier:
1423049

Lee, Jo Jo, Ghosh, Tushar K., and Loyalka, Sudarshan K.. Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air. United States: N. p., Web. doi:10.1016/j.jnucmat.2017.11.053.
Lee, Jo Jo, Ghosh, Tushar K., & Loyalka, Sudarshan K.. Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air. United States. doi:10.1016/j.jnucmat.2017.11.053.
Lee, Jo Jo, Ghosh, Tushar K., and Loyalka, Sudarshan K.. 2017. "Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air". United States. doi:10.1016/j.jnucmat.2017.11.053.
@article{osti_1423049,
title = {Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air},
author = {Lee, Jo Jo and Ghosh, Tushar K. and Loyalka, Sudarshan K.},
abstractNote = {In this paper, the oxidation rates of several nuclear-grade graphites, NBG-18, NBG-17, IG-110 and IG-11, were measured in air using thermogravimetry. Kinetic parameters and oxidation behavior for each grade were compared by coke type, filler grain size and microstructure. The thickness of the oxidized layer for each grade was determined by layer peeling and direct density measurements. The results for NBG-17 and IG-11 were compared with those available in the literature and our recently reported results for NBG-18 and IG-110 oxidation in air. The finer-grained graphites IG-110 and IG-11 were more oxidized than medium-grained NBG-18 and NBG-17 because of deeper oxidant penetration, higher porosity and higher probability of available active sites. Variation in experimental conditions also had a marked effect on the reported kinetic parameters by several studies. Finally, kinetic parameters such as activation energy and transition temperature were sensitive to air flow rates as well as sample size and geometry.},
doi = {10.1016/j.jnucmat.2017.11.053},
journal = {Journal of Nuclear Materials},
number = ,
volume = 500,
place = {United States},
year = {2017},
month = {12}
}