Effect of prior heat treatment for commercial-grade aluminum nitride powder in gas atmospheres and activating additions on the structure and properties of hot-pressed ceramics based on it

The effect of carbon-containing additions and prior heat treatment in hydro gen and nitrogen for commercial-grade AIN powder on the chemical compositio n, structure, and also some physicomechanical properties of hot-pressed cer amics based on it are studied. It is shown that hot pressing occurs mainly in the solid phase. The fracture mechanism for hot-pressed ceramics varies from intercrystalline (using unprocessed AIN powder) to predominantly trans crystalline, the grain size of the basic phase decreases, and thermal condu ctivity and strength parameters increase.