Thermal and mechanical properties of hot pressed translucent Y2O3 doped Mg-α/β-Sialon ceramics

Different Sialon phases, intergranular phase and sinterbility of additives play an important role on thermal, mechanical and optical properties of Sialon ceramics. Hot pressed translucent Mg-alpha/beta-Sialon composite was fabricated with MgO as a sintering additive. But with MgO, complete densification was not achieved because of its higher viscosity and higher melting point. Y2O3 is one of the best sintering additives to achieve complete densification and good mechanical properties in silicon nitride based ceramics. Therefore, different amount of Y2O3 was added to Mg-alpha/beta-Sialon composite and effect of Y2O3 addition on microstructure, thermal, mechanical and optical properties was investigated. alpha-Sialon phase was increased with increasing the amount of Y2O3 up to 1 wt.%, but addition of 2 wt.% Y2O3, most beta-Sialon phase was observed. Thermal conductivity and coefficient of thermal expansion values were increased with increasing the amount of Y2O3. However, translucency was decreased in higher Y2O3 addition. (c) 2013 Elsevier B.V. All rights reserved.