THERMOCHEMICAL AND PHASE EQUILIBRIA PROPERTY PREDICTION FOR OXIDE GLASS SYSTEMS BASED ON THE MODIFIED ASSOCIATE SPECIES APPROACH

摘要

The modified associate species model has proven highly versatile for reproducing phase relations, liquidus surfaces, vapor pressures, and chemical activities of relatively simple glasses. The approach treats the melt and glass as an ideal solution of constituent species, and thus easily accommodates large numbers of elements. The "modification" of the associate species model involves the treatment of immiscibility, which requires the use of a solution model with positive interaction energies and thus deviates from ideality. The global model for the glass is created by including the various species of the subsystems into single solution. The result is an accurate representation of the behavior of a complex, multi-component liquid or glass. A base glass, Na_2O-Al_2O_3-B_2O_3-SiO_2, has been well-modeled, and recently Cr_2O_3 was added to the model. Current modeling results on the inclusion of MnO and NiO are presented here.