Synergistic regulation of temperature resistance and thermal insulation performance of zirconia-based ceramic fibers

ZrO 2 fiber is a promising high-temperature resistant and heat-insulating fiber material. However, the decrease in mechanical properties caused by grain growth at high temperatures seriously affects its application. How to achieve the synergy of its temperature resistance and the thermal insulation performance is still the focus of the current industry. In this work, we started with doping inequivalent elements and studied the phase composition, temperature resistance, and thermal insulation properties of Y 2 O 3 -ZrO 2 ceramic fibers by adjusting the Y/Zr molar ratio. The results showed that Y 2 O 3 could enter the crystal lattice of ZrO 2 and form a solid solution. With the increase in Y 2 O 3 content, the structure of fibers changed from a tetragonal phase to a cubic phase, and the configurational entropy of the system increased. The larger configuration entropy in the sample could produce a robust steric hindrance effect, inhibiting grain growth. After heat treatment at 1300 °C, the grain size of Y 2 Zr 2 O 7 (Y5Z5) fibers was only 61.8% that of Y 0.1 Zr 0.9 O 1.95 (Y1Z9) fibers. The smaller grain size made the Y5Z5 fibers still have excellent flexibility and deformation recovery performance after heat treatment at 1300 °C and could still return to the original state after 85% compression or folded in half. In addition, due to the larger configurational entropy, the mean free path of phonon scattering was shortened, thereby improving the thermal insulation performance of the fiber. In short, this work achieves the synergistic effect of temperature resistance and thermal insulation properties of zirconia-based fiber materials only through simple inequivalent element doping. Graphical abstract