The effects of ball milling time on the rheological, optical, and microstructural properties of YAG transparent ceramics

Stable slurries dispersed mixture of commercial Al2O3 and Y2O3 powders, ammonium poly meta acrylate (Dolapix CE64) as the dispersant, and tetraethyl orthosilicate (TEOS) as the sintering aid were prepared by ball milling process. The effects of the milling time on the fabrication of transparent polycrystalline yttrium aluminum garnet (YAG) ceramics were investigated by slip casting and vacuum sintering. The results showed that the best milling time for the deagglomeration of the powder mixture was 16 hours and the slurry prepared during this time showed a near-Newtonian behavior due to the better deagglomeration and lower viscosity. X-ray patterns also showed that all samples were pure YAG phase. The results also revealed that the sample prepared by 16 hours ball milling time suspensions exhibited higher relative green and final density, as well as the maximum transmittance at 1064 nm (approximate to 77%). These samples had a more uniform microstructure too.