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

这项小型企业技术转移（STTR）第一阶段项目将通过实验验证热障涂层（TBC）中包含纳米结构的理论，该理论通过增加陶瓷的断裂强度从而抑制晶粒生长，从而增强对热腐蚀的抵抗力，类似于用钢筋加固混凝土。晶粒的生长导致相互连接的裂缝的形成和生长，这是熔盐抽芯所必需的，从而导致剥落。这种新型纳米复合涂层将在化石能源发电设备（肮脏燃料）和飞机发动机（海洋环境）中得到应用。目前的技术涡轮叶片由单晶镍高温合金组成。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受到从燃烧室流出的热气体的影响。涡轮入口温度的提高提高了效率、功率密度和排放质量。然而，这些保护屏障容易受到热腐蚀，高温合金和熔盐之间的电化学反应导致热障涂层剥落或破碎。减少过早剥落将允许同时增加涡轮入口温度和涡轮冷却剂空气的减少。这种组合有可能提高效率，减少有毒物质排放，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.