Drying kinetics of CeO2-ZrO2 ceramic powders under microwave heating based on a thin-layer drying model

Abstract

Abstract

Volume change of ZrO2 during martensitic phase transformation can cause cracking of material and limit the application of ZrO2.Agglomeration of CeO2-ZrO2 ceramic powders can be effectively reduced by choosing the correct drying method. Microwave drying of CeO2-ZrO2 powder can effectively reduce the cracking of zirconia materials and improve powder uniformity. Microwave heating is used to dry CeO2-ZrO2 ceramic powders, and results demonstrate that Modified Page fits experimental data rather well. FT-IR spectra revealed a remarkable decrease in the intensity of the -OH bond's stretching vibration peak, and H-O-H bond's bending vibration. Utilizing Fick's second law, the diffusion coefficient of water molecules in CeO2-ZrO2 ceramic powders with a mass of 20 g and a moisture content of 6.6 % is calculated to be 5.820 × 10−15 m2/s under microwave power of 400 W. Experimental results prove that microwave heating has low activation energy, improves drying efficiency, and realizes fast and efficient drying.