Densification and grain growth during sintering of porous Ce0.9Gd0.1O1.95 tape cast layers: A comprehensive study on heuristic methods

The sintering behavior of porous Ce0.9Gd0.1O1.95 (CGO10) tape cast layers was systematically investigated to establish fundamental kinetic parameters associated to densification and grain growth. Densification and grain growth were characterized by a set of different methods to determine the dominant sintering mechanisms and kinetics, both in isothermal and at constant heating rate (iso-rate) conditions. Densification of porous CGO10 tape is thermally activated with typical activation energy which was estimated around 440–470 kJ mol−1. Grain growth showed similar thermal activation energy of ∼427 ± 22 kJ mol−1 in the temperature range of 1100–1250 °C. Grain-boundary diffusion was identified to be the dominant mechanism in porous CGO10 tapes. Grain growth and densification mechanism were found strictly related in the investigated temperature range. Porosity acts as a grain growth inhibitor and grain boundary mobility in the porous body was estimated around 10−18–10−16 m3 N−1 s−1 at the investigated temperature range.