Abstract

Transparent YAG ceramics were prepared by slip casting an aqueous dispersed mixture of commercial Al₂O₃ and Y₂O₃ powders. The powders were co-dispersed with poly(acrylic acid) and citric acid. Polyethylene glycol of 0.5 wt.% (PEG 4000) and 0.5 wt.% tetraethyl orthosilicate were added as binder and a sintering aid, respectively. Dried samples were vacuum sintered at 1800 °C for 16 h. In general, YAG ceramics cast from Newtonian suspensions were optically transparent and had optical transmittances >80% from 340 to 840 nm. Slightly flocculated dispersions, as evidenced by higher viscosity and non-Newtonian rheology, resulted in translucent samples with large pores and lower optical transmittances.