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Cosintering (La0.84Sr0.16MnO3 thin‐film cathode/ZrO2: 8 mol% Y2O3 thin‐film solid electrolyte/55 vol.% ZrO2:8 mol% Y2O3 + 45 vol.% NiO anode, ϕ = 12 × 1.5 mm thick pellet) was achieved by applying an electric field for 5 min at 1200°C. Impedance spectroscopy measurements of the anode‐supported three‐layer cell show an improvement of the electrical conductivity in comparison to that of a conventionally sintered cell. The scanning electron microscopy images of the cross‐sections of electric field‐assisted pressureless sintered cells show a fairly dense electrolyte and porous anode and cathode. Joule heating, resulting from the electric current due to the application of the AC electric field, is suggested as responsible for sintering. Dilatometric shrinkage curves, electric voltage and current profiles, impedance spectroscopy diagrams, and scanning electron microscopy micrographs show how anode‐electrolyte‐cathode ceramic cells can be cosintered at temperatures lower than the usually required. [ABSTRACT FROM AUTHOR]

3 mol% yttria ionic conductors are sintered by applying AC electric fields with frequencies in the 0.5–1.0 kHz range at 1100 °C. The sintering experiments are conducted in pressed pellets positioned between platinum electrodes inside a dilatometer furnace. The dilatometer is modified in order to allow for the simultaneous monitoring of thickness shrinkage, electric voltage, and current across the pellet. The results show that the higher the frequency of the electric field, the higher the attained shrinkage and the apparent density of the pellets. Increasing the frequency of the applied electric field leads to an increase in the Joule heating promoted by the electric current pulse through the polycrystalline ceramic sample. A higher frequency therefore leads to higher amount of thermal energy delivered to the sample, favoring enhanced densification. The ionic resistivity decreases in pellets sintered with increasing frequency of the applied electric field. We suggest that Joule heating favors pore elimination and the removal of chemical species at the space charge region, inhibiting the blocking of oxide ions at the interfaces. [ABSTRACT FROM AUTHOR]

Electric field-assisted (flash) pressureless sintering experiments were carried out in ZrO ceramics doped with 10 mol% ScO and 1 mol% CeO (10Sc1CeSZ). All experiments were conducted isothermally at 1050 °C for 2-5 min with the application of a 100-150 V cm AC electric field at 1 kHz with 1-4 A limiting current in green compacts and in samples pre-sintered at different temperatures. Shrinkage level, structural phases and grain morphology data were collected by dilatometry, X-ray diffraction and scanning electron microscopy analyses, respectively. The results showed that for the same delivered electric power, the final shrinkage was higher for higher temperature applications of the electric field and for higher electric current pulses. Moreover, the higher the porosity, the higher the final densification of the flash-sintered 10Sc1CeSZ samples, showing that pores play a role as a preferential path in the flash sintering mechanism. [ABSTRACT FROM AUTHOR]