The Reaction Behavior of AlN Powder in Wet Air Between 1573 K and 1773 K

Abstract

The reaction behavior of aluminium nitride (AlN) powder at the temperature range of 1573 K to 1773 K in wet air was investigated using thermo-gravimetric analysis, x-ray diffraction and scanning electron microscopy. The results show that the reaction behavior of AlN powder in wet air depends on temperature and water content. Initially, weight increases quickly due to oxidation. Once the oxide product Al2O3 is formed, the volatile reaction caused by Al2O3 and H2O occurs simultaneously. Because of the appearance of cracks caused by the phase transformation of Al2O3, the reaction behavior is controlled both by oxidation and volatile reaction at a later stage. This phenomenon becomes more obvious with increasing water content. Based on the experimental result, the reaction kinetics is in reasonable agreement with the real physical picture model.