Translucent yttrium oxide ceramics from low-density green bodies shaped by uniaxial pressing

Highly compact green bodies are usually required to fabricate transparent or translucent polycrystalline yttrium oxide. The present work reports on the fabrication of highly dense (ρrel >98%) translucent Y2O3 from low-density green bodies by exploiting a high sinterability of nano Y2O3 powder. A commercial nano Y2O3, with a crystallite size of ca. 30 nm, was shaped by uniaxial pressing and, afterwards, densified by pre-sintering at 1500 °C followed by hot isostatic pressing. The coarsening tendency of yttria nanoparticles causes the rearrangement of particles and results in the high sinterability of nano Y2O3 even at low green densities. This improves the packing density and enables sintering to high densities, eliminating pores, and, thus, obtaining translucent Y2O3.