Systematic optimization of spray drying for YAG transparent ceramics

Spray drying parameters have been systematically optimized to granulate a stoichiometric mixture of commercial oxides for YAG transparent ceramics. The processing parameters and suspension composition were changed in sequence and SEM analysis, EDS, MIP and transmittance measurements, were used to choose the best spray drying parameters. The optimized inlet and outlet temperatures of drying medium were 75 and 60 degrees C, and its flux and aspiration rate were 25 Hz and 30 Hz, respectively. The balanced suspension composition were: solid content 45 wt.%, binder PVB 1.0 wt.%, dispersant DS005 0.50 wt.% and the atomizer rotating speed 8000 r/min. The granulated particles exhibited excellent forming performance with mono-dispersed, spherical and fully dense aggregates, and mean size was similar to 40 mu m. They could be crushed under 40 MPa. The homogeneous distribution and microstructure of ceramics assured the high optical quality of YAG ceramics. (C) 2015 Elsevier Ltd. All rights reserved.