Graphitization of Evaporated Carbon (in Japanese)
Pure carbon deposits were prepared by the evaporation of graphite of atomic reactor grade in a vacuum furnace and were heat-treated at temperatures between 2000 and 3000 deg C either in vacuo or under the atmospheric pressure. The lattice constants, crystal size, and orientation of graphite crystallites in the heat-treated carbons were measured by the x-ray diffraction method. The specimens were also observed under an electron microscope. The original evaporated carbon was nearly amorphous and had the turbostratic structure of relatively large graphite-like layers. The degree of graphitization of the carbons increased rapidly from 2000 to 2500 deg C and gradually above 2500 deg C up to 3000 deg C as in the case of graphitizing petroleum coke, while with the heat-treatment in vacuo the degree of graphitization changed slightly up to 2500 deg C and the graphitization took place only at temperatures higher than 2500 deg C. The degree of graphitization of carbons treated at about 3000 deg C in vacuo was found to be almost equal to that of the carbons treated at the same temperature under the atmospheric pressure. The crystallite size of the carbons changed almost parallel with the change of the lattice constant c0. The orientation of graphite crystallites parallel to the evaporated surface of the carbons increased with the heat treatment of the carbons. The effect of gas pressure on the graphitization and the change of the preferred orientation of crystallites in the carbons with the heat-treatment suggest that the process of atomic migration is one of the main factors of the graphitization process along with the translation and rotation of graphite-like layers of carbons and the coalescence of the layers.
- Research Organization:
- Nagoya Univ., Japan
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-16-017676
- OSTI ID:
- 4787458
- Journal Information:
- Kogyo Kagaku Zasshi, Journal Name: Kogyo Kagaku Zasshi Journal Issue: 12 Vol. 64; ISSN 0023-2734
- Country of Publication:
- Country unknown/Code not available
- Language:
- Japanese
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