Blister development and spallation in thermal barrier coatings

燃气轮机被广泛用于发电和推动飞机。日益稀缺的资源、保持竞争力的需要以及气候变化正在推动英国的能源市场和航空航天工业对效率、可靠性和减排提出更高的要求。作为热机，涡轮入口的气体温度要求尽可能高，以最大限度地提高效率，因此，发动机这部分的金属部件都涂有热障涂层（tbc），以防止它们熔化。燃气轮机效率、可靠性和减排的进一步提高绝对需要进一步改进tbc。优化后的tbc可以显著提高气体温度，提高效率，并且更加耐用。优化TBC的部分障碍是尚未实现对TBC失效的完整机制理解。这样的理解将有助于及时维护，避免意外停机，并支持和直接开发新的优化TBC材料系统。这项博士研究将实现对TBC中水泡发展和剥落的机制理解，旨在预测和优化TBC寿命，提高操作温度，并最大限度地减少寿命变化。

Gas turbines are widely used to generate electricity and to propel aircraft. Increasingly scarce resources, the need to remain competitive, and climate change are driving the UK's energy market and its aerospace industry to demand efficiency, reliability and emissions reduction. Being heat engines, the gas temperature at the entry to the turbine is required to be as high as possible to maximise efficiency, and consequently, metallic components in this part of the engine are coated in thermal barrier coatings (TBCs) to protect them from melting. Further increases in gas turbine efficiency, reliability and emissions reduction absolutely necessitate further improvements to TBCs. Optimised TBCs would allow significantly higher gas temperatures to increase efficiency and will be more durable. Part of the barrier to optimising TBCs is that a complete mechanistic understanding of TBC failure has not yet been achieved. Such an understanding would facilitate timely maintenance, avoid unplanned down time, and underpin and direct development of new optimised TBC material systems. This PhD research will achieve a mechanistic understanding of blister development and spallation in TBCs with the aim to predict and optimise TBC lifetime, increase operating temperature, and minimise lifetime variation.