Microstructure of (Y + Sm)–α-sialon with a-sialon seeds

(Y + Sm)–α-sialon compositions with and without α-sialon seeds were hot-pressed at 1800 °C for 1 h and then heat treated at 1800 °C for 4 h. The effect of α-sialon seeds on the microstructures of (Y + Sm)–α-sialon ceramics was studied by scanning electron microscopy. The results showed that hot-pressed α-sialon ceramics with elongated grains can be fabricated by adding 10 wt% seeds. Through heat treatment, the seed-free composition could also develop into a similar microstructure with big elongated grains dispersed in a fine matrix.