Phase stability and thermal expansion property of ZrO2–NdO1.5–AlO1.5 ceramics from 50 to 1550 °C

The phase stability and thermal expansion property of ZrO2–NdO1.5–AlO1.5 ceramics from 50 to 1550 °C were investigated for potential high-temperature structural and functional applications. All ZrO2–NdO1.5–AlO1.5 ceramics consist mainly of perovskite-like NdAlO3 and pyrochlore or fluorite (F–ZrO2) structures, and have relatively stable thermal expansion coefficients from 200 to 1400 °C. However, ZrO2–NdO1.5 (Nd2Zr2O7) ceramics have a single pyrochlore-type lattice, and exhibit a distinct decreasing tendency of thermal expansion coefficients from 400 to 1550 °C. The thermal expansion coefficients of ZrO2–NdO1.5–AlO1.5 ceramics are within the range of 10.3–11.5 × 10−6 K−1 at 1400 °C, which are of the same order of magnitude as 7 wt.% yttria stabilized zirconia.