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

Abstract

The present work investigated the phase relations in SiC-Al 2 O 3 -Y 2 O 3 -SiO 2 (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 SiO 2 in the system and its effect on the phase relations of the valuable system of SiC-Al 2 O 3 -Y 2 O 3 . The phase compositions of six solid-state reacted samples with different components of Y 2 O 3 :Al 2 O 3 :SiC:SiO 2 were analyzed by XRD. The phase relations of the systems were determined. The subsolidus phase diagrams of ternary Al 2 O 3 -SiC-SiO 2 system and the tentative phase diagram of an extended quaternary Y 2 O 3 -Al 2 O 3 -SiC-SiO 2 system were presented latter involving several coexisting regions of four phases. The high temperature reaction behavior of SiO 2 in the system and its effect on the phase relations of system were discussed.