Attaining translucency in binder/additive-free, nanograined, tetragonal 1.5 mol.% yttria-stabilized zirconia ceramics

In the quest of minimum yttria content to stabilize tetragonal zirconia system, we report the synthesis of ultrafine (-9 nm), near-spherical, phase-pure tetragonal 1.5 mol.% yttria-stabilized zirconia (1.5YSZ) nanoparticles. The pressureless sintering process (at 1100 degrees C) involved of 1.5YSZ nanopowders (without any slurry processing) and did not need any binders, additives, or sintering aid to attain high-density ( >98.5%) and refined grain size (-50 nm) for the consolidated fully tetragonal 1.5YSZ nanoceramics. A promising transmittance value of 46% (at 630 nm) was obtained, making it comparable/higher in optical properties with respect to the transmittance values of existing 3 mol.% yttria-doped ZrO2 compositions. This result is credited to our synthesized phase-pure (validated via X-ray Diffraction and Raman analysis) near-spherical nanoparticles with improved tetragonality (c/a ratio = 1.439, obtained via Rietveld analysis) that paved the way for low-temperature conventional sintering for possible large-scale industrial applications.