Ultra-fast High-temperature Sintering (UHS) of translucent alumina

Pressure-less consolidation of transparent alumina requires several hours dwelling at high temperature (1600 °C) under a strongly reducing atmosphere (hydrogen). Here, we report on the ultrafast translucent ceramics 1360 °C. Transparency was promoted by synergistic effects initial green density (62.7%) and rapid sintering using Ultra-fast High-temperature Sintering (UHS) technique. The proposed approach, heating rate 430 °C/min time 15 min, resulted in ultra-fine-grained with grain size 0.39 ?m, an in-line transmittance 28.7% wavelength 700 nm. For comparison, conventionally fired counterparts were opaque due to their incomplete densification pore coalescence.