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

(Y + Sm)-alpha-sialon compositions with and without alpha-sialon seeds were hot-pressed at 1800 degrees C for 1 h and then heat treated at 1800 degrees C for 4 h. The effect of alpha-sialon seeds on the microstructures of (Y + Sm)-a-sialon ceramics was studied by scanning electron microscopy. The results showed that hot-pressed alpha-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.