The effect of ZrO 2 alloying on the microstructures and thermal properties of DyTaO 4 for high‐temperature application

High fracture toughness of 8 YSZ (8 wt% yttria‐stabilized zirconia) is linked to its ferroelastic toughening mechanism. In this work, the similar ferroelastic domain is detected in monoclinic Dy 1− x Ta 1− x Zr 2 x O 4 ceramics, which derives from the ferroelastic transformation between the high‐temperature tetragonal (t) and low‐temperature monoclinic (m) phase. The lowest thermal conductivity of Dy 1− x Ta 1− x Zr 2 x O 4 ceramics is reduced by 30% compared with 8 YSZ, and the largest thermal expansion coefficients (TECs) is up to 11 × 10 −6 K −1 at 1200°C, which is comparable to that of 8 YSZ. Notably, the systematic investigations containing phase, microstructure, thermophysical properties of Dy 1− x Ta 1− x Zr 2 x O 4 ceramics will provide guidance for its high‐temperature application, especially as thermal barrier coatings.