Abstract:
High-Entropy ceramics (La
0.2Eu
0.2Gd
0.2Y
0.2Yb
0.2)
2Zr
2O
7 were prepared by high-temperature solid state reaction method with La
2O
3, Eu
2O
3, Gd
2O
3,Y
2O
3, Yb
2O
3 and ZrO
2 powder as raw materials. The preparation process was determined and the microstructure, phase composition, thermophysical properties of the high-entropy ceramics were studied. The high temperature thermal stability was analyzed. The results show that the dual-phase high-entropy ceramics with complete solid solution were obtained by sintering at 1 500 ℃ for 5h followed under furnace cooling. The high-entropy ceramics presented the dual-phase coexistence characteristics of pyrochlore/fluorite with grain size of 200—800 nm; the element distribution was uniform. The thermal conductivity at 800 ℃ of the high-entropy ceramics was 50% of currently used 8YSZ ceramics, and the thermal expansion coefficient was equivalent to that of 8YSZ ceramics. the high-entropy ceramics also showed excellent high temperature thermal stability.