Fabrication of Translucent Sintered Aluminum Oxynitride Spinel (AlON)

Abstract

The single-phase region of AlON, a spinel type solid solution in the system Al₂O₃-AlN, has been determined. AlON was synthesized from solid phase reactions between Al₂O₃ and AlN powder in several reaction vessels. The reaction vessel of porous Al₂O₃ with AlN coating was suitable for obtaining pure AlON. The single-phase region of AlON was from 28 to 32mol% AlN at 1700°C and from 20 to 34mol% AlN at 1800°C. The lattice parameters of AlON increased from 7.926 to 7.946Å with increasing AlN content. Y₂O₃-powder was used as a sintering aid to obtain translucent AlON from synthesized AlON powder at low temperature. For 1wt% Y₂O₃ addition, the translucent AlON was obtained at 1800°C, and its relative density and flexural strength were 99% and 250MPa, respectively.