Effect of doping on the microstructure and properties of zirconate-based emerging thermal barrier coating materials

现代燃气轮机采用热障涂层（tbc）来保护热段部件达到过高的温度。tbc的使用可以将金属表面的温度降低300°C，从而允许更高的燃气轮机工作温度，提高发动机的燃油效率和推重比，同时减少排放并延长部件寿命。对不断提高的工作温度的需求决定了需要不断研究新的和改进的tbc。由于tbc是多层系统的组成部分，因此它们必须满足许多严格的热、物理和机械性能要求，以确保设计组件的使用寿命。现有的和几种新兴的陶瓷材料都不能满足所有的要求。为了减轻这些缺陷，提出的解决方案之一是通过掺杂（类似于高温合金中的合金化）对TBC材料进行改性。因此，提出的研究计划的目标是促进我们对掺杂剂添加与当前和新兴热障涂层材料的微观结构和热、物理和机械性能之间关系的基本理解。从本研究中获得的知识将为设计微观结构和通过成分选择优化性能提供基础。通过对掺杂效应的系统评价，本研究将为选择更广泛的掺杂剂以提高性能提供科学依据，并使我们的材料选择范围超越现有材料类型的限制。

Modern gas turbines employ thermal barrier coatings (TBCs) to protect the hot section components from reaching excessive temperature. The use of TBCs can reduce the temperature on the metal surface by as much as 300°C, thereby allowing for higher gas turbine operating temperatures and achieving increased engine fuel-efficiency and thrust-to-weight ratio while reducing emissions and extending component life. The demand for ever increasing operating temperature dictates the need for continuous research into new and improved TBCs. Since TBCs are an integral part of a multiple layered system, they must satisfy many stringent thermal, physical, and mechanical property requirements in order ensure designed component life. The current and several emerging ceramic materials are not able to satisfy all the requirements. One of the solutions being proposed to mitigate many of these deficiencies is the modification of the TBC materials through doping (similar to alloying in superalloys). As such, the objective of the proposed research program is to advance our basic understanding of the relationship between dopant addition and the resulting microstructure and thermal, physical, and mechanical properties of current and emerging thermal barrier coating materials. The knowledge obtained from this research will provide the foundation on which to engineer the microstructure and optimize the properties through composition selection. Making use of a systematic approach to evaluate the doping effect, this research will provide a scientific basis on which a much wider variety of dopants may be selected for performance improvement, and expand our material choices beyond the limits of existing material types.