Modeling the effects of oxidation-induced porosity on the elastic moduli of nuclear graphites

Journal Article · Mon Sep 17 00:00:00 EDT 2018 · Carbon

DOI:https://doi.org/10.1016/j.carbon.2018.09.051· OSTI ID:1495988

Olasov, Lauren R. ^[1]; Zeng, Fan W. ^[1]; Spicer, James B.  ^[1]; Gallego, Nidia C. ^[2]; Contescu, Cristian I.  ^[2]

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1. Johns Hopkins Univ., Baltimore, MD (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Oxidation of nuclear graphites produces microstructural changes that affect the elastic moduli of these materials. It is widely accepted that the primary effect of oxidation is to increase porosity, but the related effect on the moduli cannot be explained satisfactorily by simply noting changes to porosity. In this work, models describing the elastic moduli of porous, polycrystalline graphite materials are developed to interpret experimental determinations of Young's modulus and shear modulus in two grades of nuclear graphite – IG-110 and NBG-18 – that were oxidized to produce varying levels of porosity. Experimental measurements were carried out using laser-based ultrasonic methods and were interpreted successfully using models that take into account the effects of preferential oxidation of different elements of the graphite microstructure. The results indicate the importance of the processes that lead to increased porosity since these can heavily influence the nature of the resulting structure-property relationships.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-00OR22725; 00118687
• OSTI ID: 1495988
• Alternate ID(s): OSTI ID: 1635813
• Journal Information: Carbon, Vol. 141, Issue C; ISSN 0008-6223
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE