Development of Nanoscale Coatings by Cold Gas Dynamic Spraying Techniques

燃气轮机发动机是材料系统最恶劣的运行环境之一。随着对发动机性能、效率和耐用性要求的不断提高，热障涂层(TBC)系统应运而生。然而，由于过早失效，TBC系统的全部潜力尚未达到，通常发生在粘结层/面层交界处。 根据研究活动的最新进展，该研究计划的长期目标是成功地生产出在分层/破裂方面表现出更好性能的TBC系统，并且可以大规模商业化生产。将采用三步目标来实现总体目标：1)在短期内(第1-3年)，将使用CGDS、PCGDS和改进的HVOF(热喷涂)工艺生产致密的无氧化物的常规CoNiCrAlY粘结层和纳米晶CoNiCrAlY粘结层，并将表征其在没有基材的情况下的氧化行为。2)在中期(第2-4年)，将产生类似的粘结层，它们的氧化将在底物存在的情况下进行表征。3)长期(3-5年)，将生产使用类似粘结层的完整TBC系统(包括顶层)，并对其性能进行表征。应结合性能评估进行工艺成本分析，以确定哪种工艺和哪种粉末最适合进行技术转让。

Gas turbine engines are amongst the most hostile operating environments for material systems. Increasing demands for higher engine performance, efficiency and durability have led to the development of thermal barrier coating (TBC) systems. However, the full potential of TBC systems is yet to be reached due to premature failure, usually occurring at the bond coat / top coat interface. Based on the recent progress in research activities, the long-term objective of this research program is to successfully produce TBC systems that will exhibit enhanced performances with respect to delamination/cracking and that can be produced commercially, on a large scale. A three-step objectives will be used to reach the overall goal: 1) In the short term (years 1-3), dense conventional and nanocrystalline CoNiCrAlY bond coats, free of oxides, are to be produced using the CGDS, PCGDS and modified HVOF (Warm Spray) processes, and their oxidation behaviour will be characterised, without the presence of a substrate. 2) In the intermediate term (years 2-4), similar bond coats will be produced, and their oxidation will be characterized in the presence of a substrate. 3) In the longer term (years 3-5), the complete TBC system (including the top coat) using similar bond coats will be produced, and their performance will be characterized. Process cost analysis shall be performed in conjunction with performance evaluation to determine which process and which powders are the most suitable for technology transfer.