Fabrication and properties of pink 3 mol% yttria-stabilized zirconia ceramics with high toughness

To broaden the applications of yttria-stabilized zirconia (YSZ) in mobile phone back panels and high-end decorative materials, the 3 mol% YSZ (3YSZ) ceramics doped with erbium oxide (Er₂O₃) as colorant were successfully sintered at 1250 and 1350°C in air. The influences of Er₂O₃-doping concentration and sintering temperature on the phase, microstructure, color, and mechanical properties of the pink Er₂O₃-3YSZ ceramics were investigated. As the Er₂O₃ concentration increased, the redness value a* gradually increased, while the yellowness value b* and the lightness value L* gradually decreased. The highest value a* and b* of Er₂O₃-3YSZ ceramics reached absolute values of 15.2 and 4.5, respectively. The effect of Er₂O₃ concentration is also depicted in detail, which also affects the mechanical properties including hardness and fracture toughness of the ceramics. The maximum hardness and fracture toughness of Er₂O₃-3YSZ ceramics reached 13.9 ± 0.3 GPa and 6.21 ± 0.20 MPa·m^1/2, respectively. The hardness of the ceramics exceeds 12.5 GPa, which is the required market index for further practical application. This work provides a method for preparing 3YSZ ceramics with excellent mechanical properties and bright pink color, which has the potential to be used in the fields of advanced and superior electronics in particular.