Vaporization and thermodynamic properties of ceramics based on the SrO–Al₂O₃–SiO₂ system

Abstract The vaporization behavior and thermodynamic properties of the SrO–Al 2 O 3 –SiO 2 system were investigated by Knudsen effusion mass spectrometry (KEMS) across a composition range of 10–90 mol.% SrO and Al 2 O 3 /SiO 2 molar ratios of 0.5, 1.0, and 1.5. Experiments were conducted at the temperature 2000 K using a tungsten twin effusion cell to measure partial pressures of gaseous species (Sr, SiO, O 2 ) and derive component activities, Gibbs energies, and excess Gibbs energies. The system exhibited slight negative deviations from ideality, indicative of synergistic interactions among SrO, Al 2 O 3 , and SiO 2 . Compositions with 50–60 mol.% SrO demonstrated minimized evaporation rates and enhanced thermodynamic stability, attributed to the formation of stable Sr–Al–Si–O phases. These findings provide critical insights for designing high‐temperature ceramics for aerospace applications, where thermal resilience and low volatility under extreme conditions are paramount.