Thermal Shock Behavior of Nd-Doped α-Sialon Ceramics
Nd--sialons with the stoichiometric composition of Nd0.333Si10Al¬2ON15 were obtained by hot-press sintering at 1800°C for 1h. The thermal shock behavior of the Nd--sialons was examined by a water-quenching technique. The influence of the thermal shock temperature difference (T) and cycle times on the residual strength was evaluated. Equiaxed -sialon grains formed together with a small amount of intergranular phase M (Nd2Si3-xAl¬xO3+xN4-x) and -sialon phase. The residual strength after a thermal shock tended to decrease gradually with increasing T above 500°C. However, the specimens exhibited an improved residual strength (~94% of the room temperature strength) after a thermal shock of T=1100°C. The residual strength presented a gradual decrease with increasing the thermal shock cycle times at T=1100°C, and was still remained ~55% of the room temperature strength after 11-time cycle. It is contributed to the surface oxidation which may results in the healing of surface cracks and the generation of surface compressive stresses.
Wei Pan and Jianghong Gong
C. F. Liu et al., "Thermal Shock Behavior of Nd-Doped α-Sialon Ceramics", Key Engineering Materials, Vols. 434-435, pp. 130-133, 2010