Synthesis of YAG transparent ceramics via vacuum sintering employing aluminium isopropoxide as sintering aid

In this study, aluminum isopropoxide (AIP) served as a sintering additive, and 0-10 at% AIP:YAG transparent ceramics were fabricated through vacuum sintering within the temperature range of 1650–1790 °C. It was found that after undergoing calcination at 800 °C, AIP transformed into a nanoscale γ-Al 2 O 3 coating layer on the surface of the precursor particles within the YAG green compacts. This γ-Al 2 O 3 coating layer not only accelerated the phase transformation rate of YAG but also boosted the densification rate of YAG ceramics when the temperature was below 1700 °C. Moreover, AIP was ultimately converted into α-Al 2 O 3 , thereby preventing the introduction of impurity ions. A doping concentration of 1.0–1.5 at% has been validated as an optimal range for AIP in YAG ceramics. The in-line transmittance of 1.0-1.5 at% AIP:YAG ceramics was significantly higher than that of 0 at% AIP:YAG ceramic at 1700 °C. While the temperature was further increased to 1790 °C, the positive effect of AIP became less pronounced. These findings indicate that AIP holds great promise as a sintering activity promoter for YAG transparent ceramics.