Mechanical and thermal properties of fine-grained quasi-eutectoid (La1−xYbx)2Zr2O7 ceramics

摘要: Abstract A 2 B O 7 -type rare earth zirconates have been intensively investigated as potential thermal barrier coating (TBC) materials due to their low conductivities and high stability at temperature. In this work, mixing La 3+ Yb with a large difference in atomic radii site formed quasi-eutectoid mixture of Zr -rich pyrochlore phase fluorite phase. The competition between these two phases grain growth effectively reduces the size down 0.8–1 μm, giving rise improved mechanical properties comparing single-phase materials, including higher hardness, fracture toughness lower elastic modulus. Furthermore, significantly conductivity was found, small heavy ions that dissolve could “rattle” lattice strongly scatter heat-carrying phonons. Considering comprehensively properties, (La 1− x ) ceramic can be considered TBC material.