Studies of the formation of pyrolytic carbons from gases
โ Scribed by C.F. Cullis; A.C. Norris
- Publisher
- Elsevier Science
- Year
- 1972
- Tongue
- English
- Weight
- 135 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0008-6223
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โฆ Synopsis
Samples of highly oriented pyrolytic graphite reacted with oxygen under various conditions have been studied using optical microscopy and both transmission and scanning electron microscopy. In this manner the effects of oxidation on basal and edge surfaces have been separately evaluated. The orientation and depth of etch pits have been determined. 77. Scanning electron microscopy studies of oxidized pyrolytic graphite W. S. Horton and D. B, Ballard (institute fur ~a~e~a~~ Research, h'atio~l Bureau oj Star~ards, M%Eshingtefz, D.C.
). The scanning electron microscope was used to examine pyrolytic graphite oxidized by oxygen above 600ยฐC. "Faces" sometimes contain circular holes and sometimes appear to be oxidized smoothly. Layers appear to resist oxidation to different degrees. "Edges" show separation of layers which are attacked on edges but also on exposed surfaces normal to the preferred c-direction, Some edges also show a smooth surface after oxidation.
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## A~~~-Various types of pyrolytic carbons obtained by acetylene pyrolysis at 1273 K were heat treated for 0.5 hr at 1623, 1973,2323,2673 and 3273 K. These carbons showed distinctly different ~aphit~biiity, decreasing in the order: compact, feathery, brittle, spongy and soot-like carbon. On the gr