Incongruent evaporation of ceramic-mold oxides at high temperatures and low pressures
The thermal dissociation of silicon and iron oxides, which are present in corundmn-sillimanite ceramic molds when pouring heat-temperature alloys at high temperatures, is studied. Theoretical investigations determined that the silicon present in a ceramic mold is unstable with respect to thermal dissociation at 1873 K. It was found that iron oxide will undergo intense evaporation in the melting zone at low pressures 0.65 1.33 Pa. This phenomenon increases the chemical activity of the ceramic mold in the zone of contact with heat-resistant alloys and is a source of contamination of the cast surface.
Key wordscorundum-sillimanite ceramic mold incongruent evaporation of silicon and iron oxides
- 1.S. Kulikov, Thermal Dissociation of Compounds [in Russian], Metallurgiya, Moscow (1969).Google Scholar
- 2.S. Kulikov, S. T. Rostovtsev, and É. N. Grigor’ev, Physical Chemical Fundamentals of Oxide Reduction Processes [in Russian], Metallurgiya, Moscow (1978).Google Scholar
- 3.S. Kulikov, Handbook of the Thermodynamics of Oxides [in Russian], Metallurgiya, Moscow (1984).Google Scholar