抄録
Experiments were made of the synthesis of AlN by reduction of Al2O3 with graphite powder in flowing N2 atmosphere at various temperatures between 1773 and 1973 K. At temperature below 1823 K, a temporary rise in the reaction rate was observed near the reaction degree of 50%. This discontinuous change was reflected in the residual carbon and AlN contents. At 1973 K, a small quantity of aluminum oxynitride was formed in the early stage of reaction. The reaction rate was hardly affected by the grain size of graphite, the pellet diameter and the flow rate of N2 gas. The examination of these results led to the conclusion that the diffusion of the reaction gas through the AlN layer formed around the Al2O3 grain is a major rate-determining step. Indeed, the reaction rate obeyed the rate equation which contains only the resistance of intraparticle diffusion.
