Preparation of spray-dried powders leading to Nd:YAG ceramics: The effect of PVB adhesive

The mixed powders were obtained with Al2O3, Y2O3 and Nd2O3 powders as starting materials using spray drying technology. The main purpose of introducing polyvinyl butyral (PVB) is to contribute to spray granulation of the powders and inhibition of the compositions segregation. The effect of the addition of PVB (0, 1, 2, and 3 wt%) on the morphologies and compositions of the spray-dried powders is discussed. When calcined at 1000 °C for 2 h, the powders with PVB as an adhesive show sphericity and better dispersion. No compositions segregation can be detected. It is found that the powders with 2 wt% PVB after calcinations are suitable for the fabrication of Nd:YAG transparent ceramics. The corresponding ceramics consists of a well-defined microstructure, and no pores or other defects are observed.