TY - JOUR
T1 - Densification and Grain Growth during Early-stage Sintering of Ce0.9Gd0.1O1.95-δ in Reducing Atmosphere
AU - He, Zeming
AU - Yuan, Hao
AU - Glasscock, Julie
AU - Chatzichristodoulou, Christodoulos
AU - Phair, John
AU - Kaiser, Andreas
AU - Ramousse, Severine
PY - 2010
Y1 - 2010
N2 - The present work investigates the processes of densification and grain growth of Ce0.9Gd0.1O1.95-δ (CGO10) during sintering in reducing atmosphere. Sintering variables were experimentally characterized and analyzed using defect chemistry and sintering constitutive laws. Based on the achieved results, the grain size-relative density trajectory, the densification rate, and the grain-growth rate were determined. The activation energies for densification and grain growth were evaluated, and the dominant densification mechanism was clarified. For comparison, the densification behavior of CGO10 during air-sintering was also studied. Accelerated densification was found in earlystage reducing-sintering of CGO10. This might be attributed to the oxygen vacancies generated by the reduction of Ce4+ to Ce3+ in reducing atmosphere, which facilitates the diffusion of ions through the lattice. The densification activation energy of CGO10 in reducing-sintering was evaluated as 290±20 KJ/mol in the relative density range of 0.64 to 0.82, which was much smaller than that of air-sintering (770±40 KJ/mol). The grain-growth activation energy of CGO10 in reducing-sintering was evaluated as 280±20 KJ/mol in the grain size range of 0.34 to 0.70 μm. The present work describes a systematic investigation of reducing-sintering behavior of CGO10, which contributes to the first known determination of the fundamental parameters associated with densification and grain growth during early-stage sintering of CGO10 in reducing atmosphere.
AB - The present work investigates the processes of densification and grain growth of Ce0.9Gd0.1O1.95-δ (CGO10) during sintering in reducing atmosphere. Sintering variables were experimentally characterized and analyzed using defect chemistry and sintering constitutive laws. Based on the achieved results, the grain size-relative density trajectory, the densification rate, and the grain-growth rate were determined. The activation energies for densification and grain growth were evaluated, and the dominant densification mechanism was clarified. For comparison, the densification behavior of CGO10 during air-sintering was also studied. Accelerated densification was found in earlystage reducing-sintering of CGO10. This might be attributed to the oxygen vacancies generated by the reduction of Ce4+ to Ce3+ in reducing atmosphere, which facilitates the diffusion of ions through the lattice. The densification activation energy of CGO10 in reducing-sintering was evaluated as 290±20 KJ/mol in the relative density range of 0.64 to 0.82, which was much smaller than that of air-sintering (770±40 KJ/mol). The grain-growth activation energy of CGO10 in reducing-sintering was evaluated as 280±20 KJ/mol in the grain size range of 0.34 to 0.70 μm. The present work describes a systematic investigation of reducing-sintering behavior of CGO10, which contributes to the first known determination of the fundamental parameters associated with densification and grain growth during early-stage sintering of CGO10 in reducing atmosphere.
KW - Solid Oxide Fuel Cells
KW - Fuel Cells and hydrogen
KW - Ce0.9Gd0.1O1.95-δ (CGO10)
KW - grain growth
KW - densification
KW - reducing atmosphere
KW - Brændselsceller og brint
U2 - 10.1016/j.actamat.2010.03.046
DO - 10.1016/j.actamat.2010.03.046
M3 - Journal article
SN - 1359-6454
VL - 58
SP - 3860
EP - 3866
JO - Acta Materialia
JF - Acta Materialia
IS - 11
ER -