Fabrication and microstructure of AlON ceramic by self-propagating high-temperature synthesis and isostatic pressing

The AlON compact ceramics were prepared using a new method. The fabrication of AlON composite ceramics from powder mixtures of Al and Al₂O₃ was investigated by the technology of the self-propagating high-temperature synthesis (SHS) and the hot isostatic pressing (HIP) at N₂ pressure of 100 MPa with an igniter. XRD and SEM were used for phase compositions and microstructural analysis. Result shows that, the Al₂O₃ content of a sample has a very important effect on the phase composition, the micro organization and the structure of the product. When the content of Al₂O₃ is 10wt%or 20wt%, the SHS products have obvious oscillatory combustion bedded stratification characteristics; when the content of Al₂O₃ is 30wt% or 40wt%, the products are homogeneous and compact. With the increase of Al₂O₃content, the free Al content decreases, the AlON and AlN contents increase, and the product is more compact.