| abstract |
The present invention relates to a method for preparing polycrystalline aluminum oxynitride having enhanced transparency, and more particularly, to a method for preparing polycrystalline aluminum oxynitride by sintering a powder mixture of Al 2 O 3 and AlN under atmospheric pressure, wherein the content of AlN is set to 17 to 26 mol %, a first sintering is performed at 1,575°C to 1,675°C so as to enable raw-material powders to have a relative density of 95% or higher, and a second sintering is performed so as to enable the raw-material powders to have a higher relative density. According to the present invention, all internal micropores are removed, and thus cubic polycrystalline aluminum oxynitride ceramic having a visible-light transmittance of 70% or higher can be obtained in a short amount of time at a relatively low sintering temperature. |