Granulation of Y2O3 powders by a vibration method for the preparation of transparent ceramics

A modified vibrating screen method was employed to prepare granulated Y2O3 powders, which were used to fabricate transparent ceramics. The granulation process was carried out with yttrium-stabilized zirconia balls (5 mm in diameter) in a 200-mesh screen, which was vibrated by a Heidolph shaker. After passage through the vibrating screen, the sub-micron Y2O3 particles were converted into large granules and collected in the bottom chamber of the sieve. Compared with the original powders, the granulated powders had a smaller repose angle of 34.09° and larger apparent and tap densities with sharp rises of 50.54 and 32.07%, respectively, indicating a good flowability and filling properties. A high transmittance of 82% at 2500 nm was achieved for ceramics prepared using the granulated powders by vacuum sintering and hot isostatic pressing (HIP).