Abstract
Cerium alpha -SiAlON ceramics were made from a powder mixture of Si3N4-AlN-CeO2 that contained I wt% yttrium alpha -SiAlON powder, Plasma-activated sintering was used to examine the effect of the cooling rate on the formation of alpha -SiAlON, The formation of cerium alpha -SiAlON was suggested to be controlled by the nucleation at the surface of alpha -SiAlON nuclei, because alpha -phase formation could not occur without the addition of SiAlON powder. The solubility of cerium in the alpha -SiAlON was shown to be less than a previously predicted critical value.