Flash microwave sintering of alumina

Conventional flash sintering is difficult to adapt ceramics with a very low electrical conductivity like pure alumina. Alternatively, the latter can be heated by microwave/matter interaction due dielectric losses. Microwave energy also preferable as it allows rapid contactless and volumetric heating that initiated susceptors. This work presents assembly designed for this purpose using 2.45 GHz single-mode microwave cavity original of susceptors made from silicon carbide plates 3D printed zirconia crucible. Controlled thermal cycles ranging 300 900 K/min were successfully applied while measuring shrinkage during sintering. Alumina pieces sintered up 93–98 % in mere seconds, depending on rates, microstructures discussed according “flash” conditions originally applied.