Microstructure Development of Hydrothermal Powders and Ceramics

Abstract

ZrO2 and Y-PSZ powders were prepared by the hydrothermal method. Among the hydrothermal precipitation, hydrothermal crystallization, hydrothermal hydrolysis, and hydrothermal oxidation methods, hydrothermal precipitation is an excellent method for producing Y-PSZ powder. The average crystallite size is 13–23 nm, and the surface area is 89–23 m2/g. The content of tet. ZrO2 is 75%. Hydrothermal Y-PSZ powder is sinterable at 1400°C and/or 1500°C for 2 hours. The relative density is over 99%, and the bending strength is 920–1050 MPa. The fracture toughness is 6–8 MNm−3/2. The average grain size is 0.4–0.8 µm, depending on sintering temperature. We will discuss the effect of preparation and sintering processing, especially the effect of different washing liquids and of calcination temperature, on microstructure development.