Water-assisted flash sintering: Flashing ZnO at room temperature to achieve similar to 98% density in seconds

Water can trigger flash sintering of ZnO powder pellets at room temperature to achieve similar to 98% of the theoretical density in 30 s without any external furnace heating. The specimen conductivity can be increased by >10,000 times via absorbing water vapor to enable the room-temperature flash. The initial electric field must be higher than a critical threshold to lead to densification, suggesting bifurcation in kinetic pathways. This new cost and energy saving water-assisted flash sintering (WAFS) technology can potentially be applied to consolidate other ceramic materials. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.