Thermochemical Analysis and Modeling of the Al ₂ O ₃ –Cr ₂ O ₃ , Cr ₂ O ₃ –SiO ₂ , and Al ₂ O ₃ –Cr ₂ O ₃ –SiO ₂ Systems Relevant to Refractories

Abstract

Phase diagram and chemical activity data, where available, for the Al 2 O 3 –Cr 2 O 3 , Cr 2 O 3 –SiO 2 , and Al 2 O 3 –Cr 2 O 3 –SiO 2 systems were evaluated and used in the development of models for their thermochemical behavior. Ideal, regular, and subregular solution models were used for the various solid and liquid phases in the Al 2 O 3 –Cr 2 O 3 and Cr 2 O 3 –SiO 2 systems, the Al 2 O 3 –SiO 2 having been previously modeled using the modified associate species approach. It was possible to model the Al 2 O 3 –Cr 2 O 3 liquid as an ideal solution, and compute a phase diagram and activities that resolve previous conflicts. The binary oxide systems were combined into a single set of stoichiometric phases, a corundum solid solution, and a liquid solution to represent the Al 2 O 3 –Cr 2 O 3 –SiO 2 system.