Preparation of YAG nanopowders and ceramics via coprecipitation: Effects of treatment modes of precipitates

Effects of treatment modes of precipitates in the coprecipitation method on the resulting YAG nanopowders and ceramics are investigated. Three treatment modes for precipitates, namely, single water washing, water–ethanol washing, and water washing–ethanol immersion, are conducted to prepare the YAG nanopowders. The average particle size (∼62 nm) and distribution (mainly ranging from 30 to 110 nm) of the powders obtained by the three modes are similar. However, the dispersity of the three powders shows large differences. The nanopowder obtained via water washing–ethanol immersion possesses optimal dispersity without any agglomeration, whereas that obtained via single water washing comprises substantially hard agglomerations. The relative density, Vickers hardness, and optical in-line transmittance of the ceramics prepared via water washing–ethanol immersion, respectively, reach 99.85%, 14.1 ± .4 GPa, and 77.8% at 1064-nm wavelengths after spark plasma sintering. These results are markedly superior to those of the ceramics prepared using the two other modes (97.43%, 6.8 ± .7 GPa, and 17.2% at 1064-nm wavelengths and 98.97%, 10.2 ± .5 GPa, and 47.8% at 1064-nm wavelengths, correspondingly). Therefore, water washing–ethanol immersion is a sensible and advisable treatment mode of precipitates for preparing YAG nanopowder and ceramics via coprecipitation.