Methanol-Assisted Flash Sintering of ZnO

In a prior work [Nie et al., Scripta Materialia 142, 79-82 (2018)], we have demonstrated that water vapor can trigger flash sintering of ZnO powder pellets at room temperature to achieve ~98% of the theoretical density in 30 seconds without any external furnace heating. Here, we further extend this “water-assisted flash sintering (WAFS)” to “solvent-assistant flash sintering (SAFS)” using methanol as an example. Specifically, we successfully demonstrated that methanol vapor can also trigger a flash at room temperature to subsequently sinter ZnO to ~ 93 – 96% of the theoretical density in <30 seconds. We further revealed a couple of interesting new phenomena, including bifurcation in kinetic pathways and self-termination of flash sintering.