STTR Phase I: Demonstration of Enhanced Corrosion Resistance using a Nano-composite Thermal Barrier Coating

这个小型企业技术转移(STTR)第一阶段项目将通过实验验证这样的理论，即在热障涂层(TBC)中加入纳米结构将通过增加陶瓷的断裂强度来增强抗热腐蚀能力，从而抑制颗粒生长，类似于使用钢筋加固混凝土。晶粒长大导致相互连接的裂纹的形成和长大，这些裂纹是熔融盐芯吸所需的，从而导致层裂。这种新型的纳米复合涂层将在化石能源发电设备(脏燃料)和飞机发动机(海洋环境)中得到应用。目前的技术涡轮叶片是由单晶镍高温合金组成的。从历史上看，保护性TBC允许涡轮机在超过高温合金熔点的温度下承受离开燃烧室的热气体时运行。涡轮进口温度的提高带来了效率、功率密度和排放质量的改善。然而，这些保护屏障很容易受到热腐蚀，即高温合金和熔盐之间的电化学反应，导致热障涂层剥落或碎裂。减少过早剥落将允许同时提高涡轮进口温度和减少涡轮冷却剂空气。这种组合有可能提高效率，减少有毒排放，并节省资本成本。

This Small Business Technology Transfer (STTR) Phase I project will experimentally validate the theory that inclusion of nanostructures within the Thermal Barrier Coatings (TBC) will enhance the resistance to hot corrosion by increasing the fracture strength of the ceramic thereby inhibiting grain growth similar to reinforcing concrete with rebar. The grain growth leads to the formation and growth of interconnected cracks needed for wicking of molten salts that result in spallation. The novel nanocomposite coating would find application within fossil energy power generation devices (dirty fuel) and aircraft engines (marine environments). Current technology turbine blades are comprised of single crystal nickel superalloys. Historically, protective TBC have allowed for operation of the turbine while subjected to hot gases exiting the combustor at temperatures exceeding the superalloy melting point. The increase in turbine inlet temperature has yielded improvements in efficiency, power density, and emission quality. However, these protective barriers are susceptible to hot corrosion, an electrochemical reaction between the superalloy and molten salts resulting in spallation or fragmentation of the thermal barrier coating. The reduction of premature spalling will allow for the simultaneous increase of the turbine inlet temperature and the reduction of the turbine coolant air. This combination has the potential to increase efficiency, reduce toxic emissions, and save capital costs.