Ultrafast high-temperature sintering (UHS) of cerium oxide-based compound

Abstract

Ultrafast high-temperature sintering (UHS) is an innovative sintering technique that can densify ceramics in a few seconds, dramatically reducing the carbon footprint and firing costs. In this work, the feasibility of applying UHS in Gd-doped ceria (GDC) and GDC-Er-stabilized bismuth oxide (ESB) composite powders was investigated. At high UHS currents (22–24 A), fully dense GDC samples with a large grain size were obtained. Nonetheless, most of the GDC pellets exhibited micro/macro cracks, which were reduced by lowering the sample thickness. Interestingly, the GDC-ESB composite samples exhibit no cracks or fragmentation at all, thanks to ESB as a sintering aid. Thie samples were further characterized from an electrochemical and electromechanical point of view. The GDC-ESB material displays an ionic conductivity value of ∼1.5 × 10−2 S/cm at 600 °C and frequency-stable (0.1–350 Hz) room temperature electrostriction strain coefficient of ∼10−18 (m/V)2.

Keywords

• Gd-doped ceria
• Ultrafast high-temperature sintering
• Microstructure
• Conductivity
• Electrostriction