Preparation of Ca α-SiAlON powders with rod-like crystals by combustion synthesis

Ca α-SiAlON powders with rod-like crystals were prepared by combustion synthesis from different starting compositions. The growth mechanism of the rod-like Ca α-SiAlON crystals was investigated and two growth modes were observed. One is liquid phase precipitation, and the other is nucleation and growth on smooth surfaces of the as-developed large crystals. During the development of the rod-like Ca α-SiAlON crystals, anisotropic growth occurred with the [0 0 1] direction being the fast growth direction.