Thermal expansion of lanthanum zirconate ceramics

The high-temperature behavior of lanthanum zirconate ceramics, depending on the conditions of La2Zr2O7 synthesis and sintering was investigated. The lanthanum zirconate was synthesized by solid-state method and the ceramics were sintered at temperatures of 1500 – 1550°C with different dwell times. The thermal expansion and shrinkage activity of the ceramics were studied by dilatometric analysis. The coefficients of linear thermal expansion (CTLE) were determined in the temperature range of 200 – 1200 °C during heating and cooling. CTLE of the obtained ceramics (9·10–6 1/K) is significantly less than that of tetragonal yttria doped zirconia — YSZ (13.5 10–6 1/K). CTLE decreases with increasing ceramic density. The microhardness of the ceramics was 6.3 GPa.