Although phase relations in the Na 2O-CaO-SiO 2 system are vital to melting and thermal treatments in glass and glass-ceramics industries, the available data for thermodynamic modeling are mostly based on reports published in 1920s and 1950s. The present investigation verifies the formation of solid solutions of Na 2CaSiO 4 and Na 2Ca 2Si 2O 7 which have previously assumed to be stoichiometric compounds. The impact of these solid solutions on the features of the phase diagram were investigated using the equilibration-quenching-EDS/EPMA technique. The data were reported as liquidus projections and in isothermal sections within the temperature range of 1000 and 1400 °C. Ten primary phase fields were identified, namely SiO 2, Na 2Ca 3Si 6O 16, combeite, Na 4CaSi 3O 9ss, CaSiO 3, Na 2CaSiO 4ss, Na 2Ca 2Si 2O 7ss, Na 2Ca 6Si 4O 15, Ca 3Si 2O 7 and Ca 2SiO 4. In addition, some novel liquidus data and invariants points were examined in more detail. The fundamental data obtained can be employed for the thermodynamic reassessment of the Na 2O-CaO-SiO 2 system. The present study also discusses the findings and their impact on melting and annealing processes during the manufacture of glass and glass-ceramics.
|Tidskrift||Journal of the European Ceramic Society|
|Tidigt onlinedatum||6 jan. 2022|
|Status||Publicerad - maj 2022|