Effect of Gd2O3 on the thermal conductivity of ZrO2–4mol.% Y2O3 ceramics fabricated by spark plasma sintering

Abstract Porous and dense ZrO 2 –4 mol.% Y 2 O 3 ceramics were fabricated by spark plasma sintering at 1100 and 1500 °C. The porosity of the ceramics sintered at 1100 °C increased with the addition of ∼0–5 mol.% Gd 2 O 3 . In contrast, the ceramics sintered at 1500 °C showed full density regardless of the amount of Gd 2 O 3 addition. The fluorite-type Gd 2 Zr 2 O 7 phase was formed as the second phase in the tetragonal ZrO 2 matrix. The thermal diffusivity and thermal conductivity of sintered ZrO 2 –4 mol.% Y 2 O 3 decreased with increasing Gd 2 O 3 addition.