Characterization and synthesis of ZTA nanopowders and ceramics by rotating packed bed (RPB)

Uniform ZTA composites containing 25.5 wt% ZrO2 were firstly prepared with rotating packed bed (RPB) reactor by coprecipitation method. The effects of RPB reactor on ZTA nanopowders were also investigated and compared with conventional reactor. The nanopowders in those reactors were characterized by XRD, SEM, TEM, EDS, and XPS. The results showed that ZTA nanopowders prepared by RPB had the lowest extent of agglomeration, the most homogeneous microstructure and the narrowest particle size distribution concentrating on 28-53 nm with an average sphere diameter of 41 nm. RPB could also dramatically decrease the reaction time and then decrease the energy consumption and production costs in preparation process. A further study on the microstructures of the ceramics by SEM revealed that ceramics sintered by those nanopowders also showed the smaller ZrO2 and Al2O3 grains and the more homogeneous distribution. All the results indicated that the presented novel reactor (RPB) may provide a new way to the production of nanopowders and ceramics in the industrial application.