The effect of microstructure on air oxidation resistance of nuclear graphite

作者: Cristian I. Contescu , Tyler Guldan , Peng Wang , Timothy D. Burchell

DOI: 10.1016/J.CARBON.2012.01.040

关键词: PorosityChemisorptionThermogravimetric analysisMicrostructureNuclear graphiteChemical engineeringGraphiteMaterials scienceActivation energyBET theory

摘要: Abstract Oxidation resistance in air of three grades nuclear graphite with different structures was compared using a standard thermogravimetric method. Differences the oxidation behavior have been identified respect to both (i) rate identical conditions and derived apparent activation energy pre-exponential factor (ii) penetration depth oxidant development oxidized layer. These differences were ascribed structural between grades, particular grain size shape filler, associated textural properties, such as total BET surface area porosity distribution un-oxidized material. It also found that amount strongly bonded oxygen complexes measured by thermodesorption significantly exceeds afforded low area, therefore temperature chemisorption is not reliable method for determining sites (re)active during oxidation. The relationship microstructure its demonstrated this work underlines importance performing comprehensive characterization studies new considered candidates very high gas-cooled reactors.

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