Phase Relations in Si-Al-Y-O-C Systems

The present work investigated the phase relations in SiC-Al2O3-Y2O3-SiO2 (Si-Al-Y-O-C) system. As a continuation of our previous works, the purpose of this study is to understand the high temperature reaction behaviors of SiO2 in the system and its effect on the phase relations of the valuable system of SiC-Al2O3-Y2O3. The phase compositions of six solid-state reacted samples with different components of Y2O3:Al2O3:SiC:SiO2 were analyzed by XRD. The phase relations of the systems were determined. The subsolidus phase diagrams of ternary Al2O3-SiC-SiO2 system and the tentative phase diagram of an extended quaternary Y2O3-Al2O3-SiC-SiO2 system were presented latter involving several coexisting regions of four phases. The high temperature reaction behavior of SiO2 in the system and its effect on the phase relations of system were discussed.