Zircon-based composites produced by colloidal routes: Digital light processing and reaction sintering

Zirconium silicate (ZrSiO 4 ) is a low-cost and widely available ceramic material with excellent thermal properties. Its poor sinterability as a refractory material requires special attention in the forming and sintering methods, as well as the use of additives to favour its densification. In this work, Al 2 O 3 nanoparticle additions to zircon-based materials are used to form reinforcing crystallographic phases, such as mullite and t-ZrO 2 , by reaction sintering. It is revealed that this process is dependent on the powder shaping method. The effect of slip casting and additive manufacturing using digital light processing on the microstructure, composition and spatial disposition of the new formed crystalline phases is reported. For each shaping technique, the suspension and shaping process parameters have been optimized prior to conventional sintering and characterization of the final parts.