The results of fracture microstructure and phase analysis of the 0YN specimen after CSP at 200℃ are presented in Fig. 1a and b, respectively. Microstructural features such as the presence of aggregated Y2O3 particles can be observed in Fig. 1a. This is attributed to the applied heat and pressure following hydration of the raw powder by the distilled water during the CSP [37].In the XRD pattern of Fig. 1b, only the single-phase Y2O3 peak can be observed. This indicates poor reaction during CSP due to the stability and low solubility of Y2O3 ceramics in distilled water.