Stirring speed assisted homogenization of precipitation reaction for enhanced optical performance of Y2O3 transparent ceramics

Y2O3 transparent ceramics were fabricated from precipitated powders prepared at different stirring speeds during the precipitation process. The influence of the stirring speed on the phase component of precursors, morphology of Y2O3 powders and properties of fabricated ceramics were systematically investigated. Crystalline phase precursors of (NH4)aY(OH)b(CO3)c·H2O were prepared from 110 rpm, 220 rpm and 550 rpm respectively. But amorphous precursors of Y(CO3)(OH)·nH2O (n = 1-1.5) were observed when stirring speeds were 330 rpm and 440 rpm. Y2O3 powders prepared from 440 rpm exhibited the lowest agglomeration and the smallest grain size, and the ceramics with the optimal transmittance was accordingly obtained. The results of computational fluid dynamics software CFX showed that a more homogeneous flow field distribution without local circulations could be produced at 440 rpm, which would be benefit for the optical quality of transparent ceramics. The study would provide a considerable reference for the controllable fabrication of well-dispersibility Y2O3 powders and Y2O3 transparent ceramics.