Near complete densification of flash sintered 8YSZ: controlled shrinkage rate effects

Abstract Rate-controlled sintering of 8 mol%Y2O3-doped ZrO2 (8YSZ) polycrystals was performed by rating the current limit of alternating current (AC) electric field during a flash event; this method promotes constant linear shrinkage of the green compact with respect to the sintering time. A power dissipation peak associated with the flash event was suppressed by setting the initial current limit at 100 mA; after AC current hits 100 mA, the current limit was rated to a maximum value of 1100−2000 mA to keep shrinkage rate constant. The power dissipation behavior during the current-rating process exhibited a characteristic inverted S-shaped curve as a function of time. 8YSZ polycrystal with a near-theoretical density of 5.97 g/cm3 and a grain size of approximately 3.4 μm was produced in AC electric field (150 V/cm at 1000 Hz) with a final maximum current limit of 1150 mA as a rectangular bulk style.