About 6‐8 wt% yttria‐stabilized zirconia (YSZ) is the industry standard material for thermal barrier coatings (TBC). However, it cannot meet the long‐term requirements for advanced engines due to the phase transformation and sintering issues above 1200°C. In this study, we have developed a magnetoplumbite‐type SrAl₁₂O₁₉ coating fabricated by atmospheric plasma spray, which shows potential capability to be operated above 1200°C. SrAl₁₂O₁₉ coating exhibits large concentrations of cracks and pores (~26% porosity) after 1000 hours heat treatment at 1300°C, while the total porosity of YSZ coatings progressively decreases from the initial value of ~18% to ~5%. Due to the contribution of porous microstructure, an ultralow thermal conductivity (~1.36 W m⁻¹ K⁻¹) can be maintained for SrAl₁₂O₁₉ coating even after 1000 hours aging at 1300°C, which is far lower than that of the YSZ coating (~1.98 W m⁻¹ K⁻¹). In thermal cyclic fatigue test, the SrAl₁₂O₁₉/YSZ double‐ceramic‐layer coating undertakes a thermal cycling lifetime of ~512 cycles, which is not only much longer than its single‐layer counterpart (~163 cycles), but also superior to that of YSZ coating (~392 cycles). These preliminary results suggest that SrAl₁₂O₁₉ might be a promising alternative TBC material to YSZ for applications above 1200°C.

中文翻译：

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等离子喷涂SrAl12O19在热障涂层应用中的热物理性质和循环寿命

约6–8 wt％的氧化钇稳定的氧化锆（YSZ）是热障涂层（TBC）的行业标准材料。但是，由于1200°C以上的相变和烧结问题，它不能满足高级发动机的长期要求。在这项研究中，我们开发了一种通过大气等离子喷涂制造的磁铅石型SrAl ₁₂ O ₁₉涂层，该涂层显示出在1200°C以上的温度下仍可工作的能力。SrAl ₁₂ O ₁₉在1300°C热处理1000小时后，涂层出现大量裂纹和孔隙（孔隙率约26％），而YSZ涂层的总孔隙率则从约18％的初始值逐渐降低到5％。由于多孔微结构的贡献，即使在1300°C时效1000小时后，SrAl ₁₂ O ₁₉涂层仍可保持超低导热率（〜1.36 W m ^-1  K ^-1）。 YSZ涂层（〜1.98 W m ^-1  K ^-1）。在热循环疲劳测试中，SrAl ₁₂ O ₁₉/ YSZ双层陶瓷涂层的热循环寿命约为512个循环，不仅比其单层陶瓷涂层（约163个循环）长得多，而且还优于YSZ涂层（约392个循环）。这些初步结果表明，对于1200°C以上的应用，SrAl ₁₂ O ₁₉可能是有希望替代YSZ的TBC材料。