Plasma-flash sintering: Broadening the Horizons of Flash Sintering Techniques

Flash sintering (FS) is an electric field assisted sintering technique that enables densification of ceramics material at a reduced furnace temperature and time. In this work, we expand the capabilities of FS, by introducing and investigating plasma-flash sintering, PFS, a novel methodology that incorporates the formation of plasma prior to the flash event. PFS is conducted under a low-pressure nitrogen atmosphere and offers new processing pathways for ceramic materials. Although further research is needed to fully understand the underlying mechanism of PFS, initial findings demonstrate its ability to stabilize metastable surface phases and promote the superficial absorption of ionized species (1). Notably, PFS also enables the densification of ZnO at room temperature (RT) without any external heating, using an electric field as low as 250 V cm⁻¹ (2). This operating field is substantially lower than that required by conventional flash sintering (FS) methods, which typically need electric fields in the kilovolt-per-centimeter range to initiate the flash at RT. This reduction may mitigate common issues such as current localization, hot spots, and increased risk of mechanical failure. Furthermore, unlike other RT FS approaches, PFS does not rely on conductivity-enhancing additives or ambient moisture, thereby minimizing the risk of sample contamination.

(1) Eva Gil-González et al. Plasma-flash Sintering: Metastable phase stabilization and evidence of ionized species J Am Ceram Soc. 2025;108:e20105

(2) Eva Gil-González et al. Plasma-flash Sintering II: Flashing ZnO at room temperature using low AC voltage. J Am Ceram Soc. Accepted