Gas turbine efficiency can be improved by increasing the operating temperature and by reducing the need for cooling air, both of which are enabled by higher temperature materials. Silicon carbide based ceramic matrix composites (CMCs) have shown promise for achieving higher temperatures. However, to survive in the high-temperature high-humidity combustion environment, environmental barrier coatings (EBCs) are essential to limit silicon loss of CMCs and its associated damage. Atmospheric plasma spray (APS) is a popular process for making such coatings. In this work, an alternative deposition process is explored, specifically the solution precursor plasma spray (SPPS), where it will be shown for ytterbium monosilicate EBCs that such process directly deposits thin (< 50 μm), dense and crystalline EBC topcoats without annealing of amorphous phases as is needed in the APS process. In addition, the SPPS process allows for quick compensation of system-specific element loss observed in both SPPS and APS processes. Finally, the secondary phase present in EBCs are much smaller in size for the SPPS process and hence less likely to produce cracking compared to APS EBCs.

中文翻译：

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使用基于溶液的前驱体等离子喷涂沉积的硅酸镱环境屏障涂层

燃气轮机的效率可以通过提高工作温度和减少对冷却空气的需求来提高，这两者都可以通过更高温度的材料实现。碳化硅基陶瓷基复合材料 (CMC) 已显示出实现更高温度的前景。然而，为了在高温高湿燃烧环境中生存，环境屏障涂层 (EBC) 对于限制 CMC 的硅损失及其相关损害至关重要。大气等离子喷涂 (APS) 是制造此类涂层的常用工艺。在这项工作中，探索了另一种沉积工艺，特别是溶液前体等离子喷涂 (SPPS)，它将显示单硅酸镱 EBC 的这种工艺直接沉积薄 (< 50 μm)，致密且结晶的 EBC 面漆，无需 APS 工艺中所需的非晶相退火。此外，SPPS 过程允许快速补偿在 SPPS 和 APS 过程中观察到的系统特定元素损失。最后，对于 SPPS 工艺，EBC 中存在的第二相尺寸要小得多，因此与 APS EBC 相比，产生裂纹的可能性更小。