多元稀土氧化物掺杂二氧化锆基陶瓷材料的热物理性能

稀土氧化物(RE)掺杂氧化钇稳定二氧化锆(YSZ)是提高传统YSZ热障涂层隔热性能和高温稳定性的有效途径之一。在1500 ℃高温固相反应烧结24 h制得Gd₂O₃和Yb₂O₃多元稀土氧化物掺杂的YSZ(含3.5%Y₂O₃(摩尔分数))(GY-YSZ)陶瓷材料。采用XRD研究了GY-YSZ 陶瓷材料的晶体结构和物相组成; 采用激光脉冲法研究了Gd₂O₃和Yb₂O₃掺杂对GY-YSZ 陶瓷材料的热物理性能的影响规律。研究发现, 掺杂2.0%~3.0%Gd₂O₃和Yb₂O₃(摩尔分数)后GY-YSZ的热导率为0.90~1.15 W·(m·K)-1, 比YSZ降低30%以上, 显示了良好的隔热性能。稀土氧化物掺杂对YSZ陶瓷材料热物理性能的影响机制为: 掺杂Gd₂O₃和Yb₂O₃导致YSZ中单斜相(M)、 四方相(T)和立方相(C)含量发生变化, 同时YSZ晶格发生畸变。 

Thermophysical properties of multiple rare earth oxide co-doped zirconia-based ceramic materials

Rare earth (RE) oxides doping yttria stabilized zirconia (YSZ) is an effective path to improve the thermal-resistance and high-temperature stability of traditional ceramic YSZ thermal barrier coatings. Gd₂O₃-Yb₂O₃ co-doped YSZ (contain 3.5%Y₂O₃, mole fraction) (GY-YSZ) was prepared by sintering at 1500 ℃ for 24 h. The crystal structure and phase composition of the GY-YSZ were studied by XRD analysis. Laser flash method was used to investigate the effects of doping rare earth oxides on the thermophysical property of GY-YSZ. The results show that the thermal conductivity of the GY-YSZ doped with 2.0%~3.0% mole fraction of Gd₂O₃ and Yb₂O₃ is 0.90~1.15 W·(m·K)-1, which is reduced by 30% at least than that of YSZ and proves the higher thermal-resistance property of the GY-YSZ. The influence mechanism of doping rare earth oxides on the thermal physical property of YSZ is that co-doping with Gd₂O₃ and Yb₂O₃ results in lattice distortion and content variation of monoclinic phase (M), tetragonal phase (T) and cubic phase (C) in YSZ.