A Chemo-Thermo-Mechanics Theory: Application to High-Temperature Thermal Barrier Coatings

化学热力学理论：在高温热障涂层中的应用

• 批准号: 1063626
• 负责人: Lallit Anand
• 金额: $ 40.35万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1063626&HistoricalAwards=false
• 关键词: Chemo; Thermo; Mechanics; Theory; Application

Thermal barrier coatings are applied to superalloy turbine blades to provide thermal insulation and oxidation protection. A typical coating consists of an oxide/metal bilayer: the outer oxide layer (top-coat) imparts thermal insulation, while the metallic layer (bond-coat) affords oxidation protection through the formation of a thermally-grown-oxide at elevated temperatures. Bond-coat oxidation is the primary cause of coating failure. The goal of this research is to develop a simulation-based design capability to predict the stability and durability of thermal barrier coatings. The specific aims are to: (i) Develop a continuum-level chemo-thermo-mechanics theory for modeling the coupled diffusion-oxidation-deformation and degradation of coating systems. (ii) Numerically implement the theory and develop a robust simulation-based capability for predicting coating performance. (iii) Conduct an experimental research program to validate the predictive capabilities of the theory and simulation-based design capability. Over the past 40 years, natural-gas-combined-cycle turbine-technology has evolved to dominate large scale power generation. The main technological challenges for this technology going into the future are: (i) to improve the combustion design to reduce emissions, while raising firing temperatures beyond 1430°C (the current standard); (ii) to extend operation time between maintenance intervals; and (iii) to further improve the reliability of these complex systems. The stability and durability of single-crystal turbine blades and thermal barrier coatings in such advanced applications is not very well understood or modeled. This research will provide a theoretical basis for life-prediction and performance improvement of thermal barrier coatings in such severe environments.

热障涂层应用于高温合金涡轮机叶片以提供隔热和氧化保护。典型的涂层由氧化物/金属双层组成：外部氧化物层（顶涂层）提供隔热，而金属层（粘合涂层）通过在高温下形成热生长氧化物提供氧化保护。粘结层氧化是涂层失效的主要原因。本研究的目标是 开发基于模拟的设计能力，以预测热障涂层的稳定性和耐久性。具体目标是：（i）发展一种连续水平的化学-热-力学理论，用于模拟涂层系统的扩散-氧化-变形和退化耦合。(ii)以数值方式实现该理论，并开发基于模拟的强大功能，用于预测涂层 性能(iii)进行实验研究计划，以验证基于理论和仿真的设计能力的预测能力。 在过去的40年里，天然气联合循环涡轮机技术已经发展到主导大规模发电。未来这项技术面临的主要技术挑战是：（i）改进燃烧设计以减少排放，同时将燃烧温度提高到1430°C以上（目前的标准）;（ii）延长维护间隔之间的运行时间;（iii）进一步提高这些复杂系统的可靠性。单晶涡轮机叶片和热障涂层在这种先进应用中的稳定性和耐久性还没有得到很好的理解或建模。该研究为热障涂层在恶劣环境下的寿命预测和性能改进提供了理论依据。