Solid-liquid equilibria in the silicon-rich corner of the Si-O-C system

A phase diagram is proposed for the solid-liquid equilibria in the silicon- rich corner of the SI-O-C system. It is calculated from the solubility data in binary systems, using the model of a regular solution to estimate the i nteraction coefficient from existing standard reaction data. The solubility of carbon in solid and liquid solutions saturated with SiC is slightly inc reased by the effect of oxygen. A similar conclusion holds for the effect o f carbon on oxygen solubility in solutions saturated with SiO2. The effect of the third element on the partition coefficient of carbon or of oxygen is negligible. The main result of the proposed diagram is the finding that th e solubility can be limited either by SiO2 saturation or by SIC saturation according to the carbon-to-oxygen ratio.