Fabrication of Al2O3-Y3Al5O12-ZrO2 composites by single-step spark plasma sintering

Fabricating Al 2 O 3 -Y 3 Al 5 O 12 -ZrO 2 ceramic composites with a eutectic microstructure is challenging and costly, as it requires high-temperature melting of precursor materials. Here, we report on the successful production of Al 2 O 3 -Y 3 Al 5 O 12 - 5 mol% ZrO 2 composites with lamellar eutectic microstructure through single-step spark plasma sintering (SPS) of sol-gel synthesized powder. The release of volatile species from partially calcined powders, due to limited calcination at 1000°C for 2 h, as well as their fine particle size, were used to create the conditions for local electric discharge and plasma formation during SPS; this resulted in the local formation of eutectic liquids, enabling the formation of lamellar microstructures. The microstructural features can be tailored by modifying the calcination process.