Advanced Thermal Barrier Coating Systems for Gas Turbine Application: Microstructure, Properties, and Performance

在航空航天和发电行业，降低燃料消耗、运营成本和温室气体排放的需求继续推动燃气轮机发动机(GTE)设计者寻找提高GTE效率和延长运行寿命的方法。提高汽轮机进口温度是在不增加燃料消耗的情况下增加功率输出的关键途径。随着汽轮机进口温度的升高，对恶劣环境下连续运行的要求，以及向替代燃料的转变，热截面材料正受到更大的机械应力和环境侵蚀。虽然用于制造涡轮叶片、叶片和燃烧部件的最先进高温合金可以在高达1093°C(2000°F)的温度下保持强度，但大多数当前和所有下一代GTE设计都要求材料能够在此温度之后安全运行。只有使用热障涂层(TBC)系统和冷却技术才能做到这一点。此外，许多现代高温合金由于较低的铬含量而降低了耐环境性能，这是为了在更高的温度和机械载荷下稳定组织。因此，热障涂层现在被要求兼具隔热和环保功能，并已成为现代热障涂层不可或缺的组成部分。随着行业将TBC指定为GTE设计中的“主要依赖项”的目标，需要进一步提高TBC的性能和可靠性。

In the aerospace and power generation industries, demands to reduce fuel consumption, operating costs, and greenhouse gas emissions continue to push gas turbine engine (GTE) designers to find ways to improve GTE efficiency and extend operating lives. Increasing the turbine inlet temperature is a key way to increase power output without increasing fuel burn. With rising turbine inlet temperatures, demands for continuous operation under harsh environments, and a shift towards alternative fuels, hot section materials are being subjected to increased mechanical stresses and environmental attack. While state-of-the-art superalloys used to manufacture turbine blades, vanes, and combustion components can maintain strength at temperatures up to 1093°C (2000°F), most current and all next generation GTE designs require materials that can safely operate well beyond this temperature. This is only possible with the use of thermal barrier coating (TBC) systems and cooling technology. In addition, many modern superalloys have reduced environmental resistance due to lower Cr content, done to stabilize the microstructure under higher temperatures and mechanical loads. Therefore, TBCs are now required to provide both thermal barrier and environmental protection functions, and have become integral to modern GTEs. With the industry’s goal to designate TBCs as a “prime reliant” in GTE design, further TBC performance improvement and reliability are needed.