Electric‐Field‐Assisted Versus Conventional Sintering of 8YSZ: Densification Kinetics, Microstructure, and Functional Properties

A comparison of the sintering behavior of 8 mol% yttria‐stabilized zirconia (8YSZ) processed via conventional sintering (CS), spark plasma sintering (SPS), and flash sintering (FS) is presented. The objective was to evaluate the influence of electric‐field‐assisted techniques on densification kinetics, grain growth, mechanical properties, and ionic conductivity under processing conditions. Conventional sintering achieved ~98.5% relative density at 1400 °C with a 2 h dwell, whereas FAST/SPS enabled comparable densification at 1300 °C within 10 min under a 50 MPa load. Flash sintering produced similar densification at a reduced furnace temperature of 850 °C within 60 s at an optimized current density of 140 mA/mm 2 , corresponding to a specimen temperature of ~1293 °C. Field‐assisted methods, characterized by high heating rates, promoted rapid densification while limiting grain growth, resulting in finer microstructures than conventional processing. Despite differences in processing temperature and duration, hardness (13–15 GPa) and total ionic conductivity (~10 −4 S/m at 350 °C) were comparable for all three routes. These findings indicate that once near‐theoretical density is achieved, mechanical and electrical properties of 8YSZ are largely independent of sintering pathway. The reduction in furnace temperature and processing time achieved through electrification highlights flash sintering as an energy‐efficient strategy for manufacturing dense 8YSZ without compromising functional performance.