Controlled crack growth in an oxidized nuclear grade graphite
Controlled crack growth in an oxidized nuclear grade graphite
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DOI：
10.1088/0022-3727/37/22/022
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发表时间：
2004-11
期刊：
影响因子：
--
通讯作者：
P. Ouagne;G. Neighbour;B. Mcenaney
中科院分区：
文献类型：
--
作者：
P. Ouagne;G. Neighbour;B. Mcenaney
Curves of the crack growth resistance parameters KR, JR and R as a function of crack length were obtained for IM1-24 nuclear grade graphite subject to oxidation in CO2 at 900°C up to 20% burn-off. For the unoxidized graphite, the curves show three regions: (i) an initial rise attributed to the development of bridging in the crack wake zone, (ii) a plateau region where the process zone ahead of the crack tip and the crack bridging zone reach steady states and (iii) falling R and JR curves (or a rising KR curve) when the crack tip approaches the back of the edge specimen. For oxidation up to ~11% burn-off, the values of R, JR and KR decrease progressively and the plateaux become shorter. At higher burn-off values, the plateau is not found. These trends indicate that the process zone size increases progressively with oxidation, but the length of the crack bridging zone remains unaffected by oxidation at least up to 10% burn-off. The initial values of R and KR, are close to the values of the linear elastic fracture parameters KIc and GIc, respectively.
