Effect of CaTiO3 on sintering properties of Y2O3 -based ceramic shell via extrusion-based 3D printing for titanium alloy casting

Yttrium oxide (Y2O3) is widely used in titanium (Ti) alloy casting for its low activity, strength, and heat resistance. Wax mold and ceramic coating preparation in traditional investment casting is cumbersome; hence, this work proposes extrusion-based 3D printing of Y2O3-based ceramic shells. This study investigates how trace CaTiO3 affects sintering performance, showing that small amounts can reduce sintering temperature and significantly increase bending strength. Adding 2 mol% CaTiO3 increased the bending strength from 4.3 to 43.1 MPa after sintering at 1500 °C, while not wetting with the Ti–6Al–4V titanium alloy. This method offers a promising way to produce high-performance Y2O3-based ceramic shells with lower sintering temperatures.