The early stages of oxidation in I_w-phase Y-Si-Al-O-N glass-ceramics

摘要

The use of Si_3N_4 and SiAlON materials at high temperatures is restricted by the tendency for these materials to suffer from oxidation under such conditions. Previous studies of oxidation of SiAlON glasses and glass-ceramics have shown that they oxidise with the formation of a porous crystalline scale, and that the rate is reaction controlled, limited by the progress of the internal interface between the scale and the bulk. TEM based characterisation of the microstructural processes occurring beneath the oxide scale on SiAlON glass ceramics has not previously been reported. This paper concens microstructural evolution during the early stages of oxidation of Y Iw glass-ceramics.