Oxidation Behavior of Y2O3 and Er2O3-doped-α/β-SiAlON Ceramics

SiAlON ceramics are successfully utilized in applications such as refractories used for metal melting and cutting tools for high speed machining of metals in which high temperature properties are important. As being one of the main indication of high temperature resistance for such applications, oxidation resistance of this materials are affected by microstructural features, type and amount of the rare-earth (RE) elements in α-SiAlON and grain boundary phase (GBP). In this study, oxidation behavior of α/β-SiAlON ceramics prepared by Er2O3 as well as Y2O3, which is one of the most widely used RE-oxide in commercial SiAlON compositions, was investigated comparatively. A slight difference was observed in oxidation resistance of Er2O3 and Y2O3 containing SiAlON ceramics due to their slightly different crystallinity of GBPs