|
| Effects of ZrO2 Doping on Mechanical and Thermo-physical Properties of La2Ce2O7 Ceramics |
| Received:March 01, 2019 Revised:April 12, 2019 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7643/issn.1672-9242.2019.10.004 |
| KeyWord:thermal barrier coating (TBC) La2Ce2O7 (LC) mechanical property thermo-physical property |
| Author | Institution |
| DAI Jian-wei |
Key Laboratory for Advanced Corrosion and Protection of Aviation Materials, AECC, Beijing Institute of Aeronautical Materials, Beijing , China |
| MU Ren-de |
Key Laboratory for Advanced Corrosion and Protection of Aviation Materials, AECC, Beijing Institute of Aeronautical Materials, Beijing , China |
| WANG Xin |
Key Laboratory for Advanced Corrosion and Protection of Aviation Materials, AECC, Beijing Institute of Aeronautical Materials, Beijing , China |
| XU Zhen-hua |
Key Laboratory for Advanced Corrosion and Protection of Aviation Materials, AECC, Beijing Institute of Aeronautical Materials, Beijing , China |
| HE Li-min |
Key Laboratory for Advanced Corrosion and Protection of Aviation Materials, AECC, Beijing Institute of Aeronautical Materials, Beijing , China |
|
| Hits: |
| Download times: |
| Abstract: |
| Objective To improve the fracture toughness of La2Ce2O7 (LC) ceramics materials. Methods Yttria stabilized zirconia (YSZ) doped La2Ce2O7 (LC) materials (LCZ) were synthesized by solid-state sintering. The mechanical properties including Young’s modulus and fracture toughness and thermo-physical properties including thermal expansion coefficients and thermal conductivities were investigated. Results The fracture toughness of 10mol% YSZ-doped LC sample was about 1.4 MPa.m1/2, nearly 10% higher than that of the undoped LC sample. The sudden drop in TECs of LC at 200-400 ℃ was effectively constrained by YSZ doping, and the TECs of the LCZ sample were 10×10-6-12×10-6 K-1 at 200-1200 ℃. The thermal conductivity of the LCZ sample was about 0.75 W/(m.K) at 1200 ℃, at least 50% lower than that of the YSZ sample, presenting good heat-insulating property. Conclusion By YSZ doping, La3+ in LC in is replaced by Zr4+, the O vacancy concentration in the space is decreased and the lateral shear movement of atom is weakened, effectively restraining the decrease of thermal expansion coefficient of LC at 200-400 ℃. Since t-ZrO2→m-ZrO2e has indirect healing effect on light crack, the 10%YSZ effectively improves the fracture toughness of LC pieces. |
| Close |
|
|
|