Processing of Aluminum Oxynitride Through Aqueous Colloidal Forming Techniques

Abstract

Aqueous colloidal forming techniques like slip/gel casting have been attempted to prepare monoliths of aluminum oxynitride (AlON) starting from the constituent raw materials of high‐purity alumina and aluminum nitride. A surface treatment conducive to prevent hydrolysis of aluminum nitride in an aqueous medium was carried out before the shaping technique. The slurry, leading to an AlON composition of Al 23 O 27 N 5 , was prepared with high solid loading (76–80 wt%) in water and casted into molds, dried, and sintered in the temperature range 1725°–1925°C in a nitrogen atmosphere. AlON phase formation was followed by XRD and it was observed that phase‐pure AlON was obtained at temperatures above 1825°C. The samples were further characterized for mechanical and microstructural properties.