Commercially available Y2O3 powder was subjected to size and shape control followed by carrying out densification for 5 min at relatively lower temperatures (1400-1700 oC) using a spark plasma sintering (SPS) system to examine the optimum sintering conditions. The results showed that the specimen sintered at 1600 oC for 5 min while being pressurized at 30 MPa exhibited the highest sintering density (98.97%) and demonstrated the best transmittance performance. The annealing treatment of samples at oxygen atmosphere was very effective to increase their transmittance. The increased transmittance could be attributed to the decrease in oxygen vacancy and the removal of surplus carbon. Samples exhibiting superior mechanical properties and a high transmittance of 82.15% (i.e., 99% of the theoretical value) at a wavelength of 2000 mm were obtained.

Keywords: Y2O3 Transparent ceramics, Spark plasma sintering, Densification, Microstructure.