Blister development and spallation in thermal barrier coatings

燃气轮机广泛用于发电和推进飞机。日益稀缺的资源、保持竞争力的需求以及气候变化正在推动英国能源市场及其航空航天业对效率、可靠性和减排的需求。作为热力发动机，在涡轮机的入口处的气体温度需要尽可能高以使效率最大化，因此，发动机的该部分中的金属部件涂覆有热障涂层（TBC）以保护它们免于熔化。燃气涡轮机效率、可靠性和排放减少的进一步提高绝对需要进一步改进TBC。优化的热障涂层将允许显著更高的气体温度，以提高效率，并将更加耐用。优化TBC的部分障碍是尚未实现对TBC故障的完整机械理解。这种理解将有助于及时维护，避免计划外停机时间，并支持和指导新的优化TBC材料系统的开发。这项博士研究将实现对TBC中气泡发展和气泡形成的机械理解，旨在预测和优化TBC寿命，提高工作温度，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.