Porosity analysis of superfine-grain graphite IG-110 and ultrafine-grain graphite T220

ABSTRACT

Gas-escape pores in nuclear graphite IG-110 and T220 were characterized by using optical microscopy. It is proved that reliable size distribution of pores can be derived by processing optical images of graphite. The results were compared with those obtained from mercury porosimetry test and X-ray tomography. Optical microscopy showed that the majority of IG-110’s (T220’s) porosity is contributed by pores with sizes around 13 (3) µm, which was confirmed by X-ray tomography for IG-110. But, mercury porosimetry test indicated that pores with sizes around 2.3 (0.9) µm contribute the majority of IG-110’s (T220’s) porosity. The difference between mercury porosimetry and the other two techniques suggests that the graphite pores are connected by relatively thinner channels.

KEYWORDS:

• Nuclear graphite
• gas-escape pores
• optical microscopy

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Hui Tang http://orcid.org/0000-0002-4997-0767

Additional information

Funding

This work is supported by the National Natural Science Foundation of China (11505265), Youth Innovation Promotion Association CAS (2019262) and the strategic priority research programme of Thorium-based Molten-salt Reactor (TMSR) [grant number XDA02040100].