Effect of powder milling routes on the sinterability and optical properties of transparent Y2O3 ceramics

In ceramic processing, the size distribution of the starting powder to a certain degree is inevitable. It is prerequisite to control the size distribution, which influences the fabrication of a sound green body featuring both smaller pores and a narrower pore structure for full-density sintering facilitated by the easier elimination of pores. The milling process was systematically investigated here to elucidate the effect of powder characteristics on the sinterability and transmittance of Y2O3 ceramics. Three types of powder sets having different width of particle size distribution (W-PSD) while keeping the same median size (D-50) were prepared by changing the milling condition. By means of narrowing the WPSD in this research, pore free transparent polycrystalline Y2O3 with average grain size of 730 nm was successfully fabricated by hot-pressing at 1500 , which is 100 lower than the previously lowest known sintering temperature.