Microstructure and Properties of Densified GdO Bulk.

In this work, GdO bulks were sintered at temperatures ranging from 1400 °C to 1600 °C for times from 6 h to 24 h, and their microstructure and properties were studied for a wider application of materials in thermal barrier coatings. The densification of the GdO bulk reached 96.16% when it was sintered at 1600 °C for 24 h. The elastic modulus, hardness, fracture toughness and thermal conductivity of the bulks all increased with the rise in sintering temperature and extension of sintering time, while the coefficient of thermal expansion decreased. When the GdO bulk was sintered at 1600 °C for 24 h, it had the greatest elastic modulus, hardness, fracture toughness and thermal conductivity of 201.15 GPa, 9.13 GPa, 15.03 MPa·m and 2.75 W/(m·k) (at 1100 °C), respectively, as well as the smallest thermal expansion coefficients of 6.69 × 10/°C (at 1100 °C).