Rudi Metselaar

Solubility of carbon in liquid Al and stability of Al4C3

Abstract Using thermodynamic models the properties of the AlC liquid phase have been evaluated from experimental information on the carbon solubility in liquid Al. After slight modification of the description of Al4C3 presented by Gluschko and Gurvitch [1], the solubility has been described very well from 950 to 2500 °C with a regular solution model for the liquid phase. Stability of Al4C3 was examined through thermodynamic calculations under various conditions. It has been shown that the description of Al4C3 can account very well for most thermochemical measurements in a wide temperature range.

Reactions in the CaOCs2OAl2O3 system at 900°C

Abstract Reactions in the system CaOCs 2 OAl 2 O 3 were investigated. On the basis of the experimental results, a compatibility diagram for this system at 900°C is proposed. In this system a new compound was found and formulated as Cs 2 O.2CaO.4Al 2 O 3 . The X-ray diffraction pattern was measured and the cell parameters were derived. The phase relation results can be used to draw some conclusions about the caesium compatibility of Al 2 O 3 containing calcia. We found that all calcium aluminates react with Cs 2 O forming a stable compound. From these results we conclude that calcium will have a negative effect on the caesium resistance of Al 2 O 3 .