TBC Bond Coat Properties and Dynamics

该基金承担了一项实验研究，以阐明和模拟一类新的热障涂层（TBCs）粘结层材料的机械行为和热稳定性。TBC的关键组成部分之一是其粘结层，并且有明确的经验证据表明，铂添加到铝化物粘结层中可以提高这些涂层的整体性能和可靠性。据信其他铂族金属（Pd、Ru、Ir、Rh和Os）提供类似或甚至更大的益处，但目前还不清楚控制粘合涂层性能的机制。拟议的研究将平行和恭维一个更大的NSF-EC合作计划的层状多功能表面的动力学。NSF-EC研究的一个方面涉及铂族金属粘结涂层的加工和相平衡方面，目前的研究将与NSF-EC团队密切合作进行，以表征Ru基合金和粘结涂层的机械行为和微观结构演变。该补助金支持首席研究员和研究生参加年度研讨会，并与NSF-EC团队合作，扩大欧洲国家和美国之间的学生互访。该研究计划的总体重点是测量单相Ru-Ni-Al-Xn和钌改性粘结涂层的性能，以基本了解热循环过程中发生的基材-粘结涂层相互作用（相互扩散，粘塑性，形态演变，裂纹形成等）。并推导出一个基于科学的协议，用于评估钌改性粘结涂层的潜力并协助其开发。在本研究中使用的微量样品拉伸试验方法允许表征小规模和高度规模特定的涂层和性能（弹性模量，屈服和蠕变强度）的方式不可能通过常规手段。该提议的技术动机源于这样一个事实，即热障涂层为提高燃气涡轮机发动机的温度能力和耐久性提供了巨大的机会。通过参加年度研讨会和扩大互访，参与该项目的学生将获得宝贵的经验，了解美国和欧洲如何进行研究。

This grant undertakes an experimental study to elucidate and model the mechanical behavior and thermal stability of a new class of bond coat materials for thermal barrier coatings (TBCs). One of the key components of a TBC is its bond coat, and there is clear empirical evidence that platinum additions to aluminide bond coats enhance the overall performance and reliability of these coatings. Other platinum group metals (Pd, Ru, Ir, Rh, and Os) are believed to provide similar or even greater benefits, but the mechanisms that govern bond coat performance are currently not well understood. The proposed study will parallel and compliment a larger NSF-EC collaborative program on the dynamics of layered multifunctional surfaces. One aspect of the NSF-EC study involves processing and phase equilibria aspects of platinum group metal bond coats, and the current study will be conducted in close collaboration with the NSF-EC team to characterize the mechanical behavior and microstructural evolution of Ru-based alloys and bond coats. The grant supports for the principal investigator and graduate students to participate in annual workshops and collaborations with the NSF-EC team with extended reciprocal visits of students between European Countries and US. The overall focus of this research program will be to measure single-phase Ru-Ni-Al-Xn and ruthenium modified bond coat properties, to develop a fundamental understanding of the substrate-bond coat interactions that occur during thermal cycling (inter-diffusion, viscoplasticity, morphological evolution, crack formation, etc.) and to derive a science-based protocol for assessing the potential and assisting in the development of ruthenium modified bond coats. The microsample tensile testing approach to be used in this study permits characterization of small-scale and highly scale-specific coatings and properties (elastic modulus, yield and creep strength) in a way not possible by conventional means. The technological motivation for this proposal is rooted in the fact that TBCs offer tremendous opportunities for increasing the temperature capabilities and durability of gas turbine engines. Through the proposed participation in annual workshops and extended reciprocal visits, the students working on this project will gain valuable experience into how research is conducted in both the U.S. and Europe.