Translucent alumina ceramics with high transparency were successfully prepared via gelcasting and vacuum
sintering. Effects of powder properties and copolymer content on solids loading of the slurry and
then on the porosity, microstructures of both green bodies and sintered ceramics, as well as optical transmittance
of the final ceramics were extensively investigated. Fine and de-agglomerated alumina powder
was effective to prepare slurries with higher solids loading. They resulted in lower porosity (higher relative
density) and smaller pore size in green bodies. After sintered at 1860 C for 6 h in vacuum, the resultant
ceramics from higher solids loading had less residual pores. In-line transmittance of the ceramic
(1 mm thick) from 55 vol% solids loading reached as high as 53.6% at 600 nm, much higher than previously
reported data (