Effect of Metals on Formation of Graphite Crystals

Abstract

The reactions between carbon and metals such as thermal black (T.B.) and silicon, T.B. and iron etc. were investigated by means of X-ray diffraction and chemical analysis.
The (002) diffraction profile of the sample had two peaks, one of which was attributable to heat-treated T.B. and the other to graphite. This fact constitutes that the sample is a mixture of heat-treated T.B. and graphite crystals. So, the quantity of formed graphite crystals was estimated by using as a standard a heat-treated T.B. and a natural graphite mixture of a known ratio.
From the quantitative relationship between formed graphite and residual matter it was considered that silicon forms graphite crystals by formation and decompostion of silicon carbide and iron segregates graphite crystals from iron-carbon melt. The curve of quantity of formed graphite vs. heating time a unique feature according to the kind of metal, and in this connection, it was considered that metals can be divided into two types, that is silicon-type and iron-type. Also, it was found that no marked increase in the quantity of formed graphite can be expected as a result of repeated reaction between carbon and metal.