Parchovianský Milan, Parchovianská Ivana, Hanzel Ondrej, Netriová Zuzana, Pakseresht Amirhossein
Centre for Functional and Surface Functionalised Glass, Alexander Dubček University of Trenčín, Študentská 2, 911 50 Trenčín, Slovakia.
Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 36 Bratislava, Slovakia.
Materials (Basel). 2022 Apr 12;15(8):2839. doi: 10.3390/ma15082839.
In this work, La2Ce2O7-yttria-stabilized zirconia (LC-YSZ) composites with different weight fractions of YSZ (40−70 wt.%) were prepared by hot pressing at 1400 °C and investigated as a material for thermal barrier-coating (TBC) applications. For this purpose, the effect of YSZ addition on the phase composition, microstructure, mechanical performance and thermal behavior was studied. X-ray diffraction analysis showed that the LC-YSZ composites were mainly composed of a cubic ZrO2 and La2O3-CeO2-ZrO2 solid solution with a pyrochlore structure, indicating that the reaction between LC and YSZ took place during hot pressing. Scanning electron microscopy revealed the high microstructural stability of the prepared composites, as the pore formation was significantly controlled and a high relative density (>97%) was obtained. The microstructure of LC-YSZ bulk samples was relatively fine-grained, with an average grain size below or very close to 1 µm. YSZ doping improved the Vickers hardness of the LC-YSZ composites; the highest hardness, with value of 12 ± 0.62 GPa, was achieved for the composite containing 70 wt.% of YSZ. The fracture toughness of LC-YSZ composites was in the range from 2.13 to 2.5 MPa·m1/2. No statistically significant difference in heat capacity or thermal conductivity was found between the composites with different content of YSZ. The results showed that LC-YSZ composites have relatively low thermal conductivities from room temperature (1.5−1.8 W·m−1·K−1) up to 1000 °C (2.5−3.0 W·m−1·K−1). This indicates that the prepared LC-YSZ composite materials are promising candidates for TBC applications.
在本研究中，通过在1400℃下热压制备了具有不同重量分数的氧化钇稳定氧化锆（YSZ，40 - 70 wt.%）的La2Ce2O7 - 氧化钇稳定氧化锆（LC - YSZ）复合材料，并将其作为热障涂层（TBC）应用的材料进行了研究。为此，研究了YSZ添加量对相组成、微观结构、力学性能和热行为的影响。X射线衍射分析表明，LC - YSZ复合材料主要由立方ZrO2和具有烧绿石结构的La2O3 - CeO2 - ZrO2固溶体组成，这表明LC与YSZ之间的反应在热压过程中发生。扫描电子显微镜显示所制备的复合材料具有高微观结构稳定性，因为孔隙形成得到了显著控制，并且获得了高相对密度（>97%）。LC - YSZ块状样品的微观结构相对细晶，平均晶粒尺寸低于或非常接近1 µm。YSZ掺杂提高了LC - YSZ复合材料的维氏硬度；对于含有70 wt.% YSZ的复合材料，实现了最高硬度，值为12±0.62 GPa。LC - YSZ复合材料的断裂韧性在2.13至2.5 MPa·m1/2范围内。在不同YSZ含量的复合材料之间，未发现热容或热导率有统计学上的显著差异。结果表明，LC - YSZ复合材料从室温（1.5 - 1.8 W·m−1·K−1）到1000℃（2.5 - 3.0 W·m−1·K−1）具有相对较低的热导率。这表明所制备的LC - YSZ复合材料是TBC应用的有前途的候选材料。
