GOALI: Comibinatorial Methods and Micro-Scale Characterization Techniques for TBC Optimization

这项由约翰霍普金斯大学材料研究部提供的GOALI资助，将采用组合方法和微尺度测试来阐明合金化学对用于高温合金的热障涂层（tbc）粘结层中马氏体转变的作用。有了这个奖项，Hemker教授和Zhao教授将为粘合层设计开辟一个新的范例，他们的研究将促进实验工具的发展，将新材料推进到各种结构应用中。这项拨款的动机是最近发现马氏体转变发生在热循环，铂改性，镍铝化物结合涂层。这种转变已被证明会极大地影响TBC的性能，并且已知高度依赖于合金化学，这可能因元素相互扩散而变化。扩散倍数的使用为澄清化学计量学和三元元素（如铂、铬、铼、钨、钼、钽、钴和铪）在控制马氏体形成中的作用提供了一种高效的手段。通过惰性等离子体沉积制备特定成分的靶向薄膜组合样品，并通过一系列新的微尺度表征技术（微拉伸测试、纳米压痕、微探针光谱、差热分析、x射线衍射和透射电子显微镜）进行表征。该结果将为TBC涂层中马氏体转变提供基本的理解，从而为开发持久、高性能的TBC涂层提供科学的方案。这项研究的技术动机源于这样一个事实，即热障涂层为提高飞机发动机和动力涡轮机部件的温度能力和耐久性提供了巨大的机会。此外，需要解决的科学挑战，即开发用于评估多层涂层稳定性、强度和性能的组合方法和新型微尺度表征技术，对多组分结构材料的开发具有更广泛的应用。这项与工业界学术联络的资助机会（GOALI）合作包括紧密结合的研究活动和年度人员交流，并使约翰霍普金斯大学的学生和教师与GE全球研究中心的工程师和科学家直接接触。通过提供宝贵的技术和工业经验，这拓宽了JHU学生的教育。通用电气的好处包括获得JHU独特的实验专业知识，以及专注于高科技领域的基础研究的能力。

This GOALI grant from the Division of Materials Research to Johns Hopkins University is to employ combinatorial methods and micro-scale testing to elucidate the role of alloy chemistry on the martensite transformation in bond coats for thermal barrier coatings (TBCs) applied to superalloys. With this award, Professors Hemker and Zhao will be opening a new paradigm for bond coat design, and the research will promote the development of experimental tools needed to advance new materials into a variety of structural applications. This grant is motivated by the recent discovery of martensite transformation occurring in thermally cycled, platinum modified, nickel aluminide bond coats. This transformation has been shown to dramatically influence the performance of the TBC and is known to be highly dependent on alloy chemistry, which can vary as a result of element interdiffusion. The use of diffusion multiples provides a highly efficient means for clarifying the role that stoichiometry and ternary elements (e.g. Platinum, Chromium, Rhenium, Tungsten, Molybdenium, Tantalum, Cobalt and Hafnium) will have in governing martensite formation. Targeted thin film combinatorial samples of specific compositions, determined using diffusion multiples, are fabricated with inert plasma deposition and characterized with a suite of novel micro-scale characterization techniques (micro-tensile testing, nanoindentation, micro-probe spectroscopy, differential thermal analysis, X-ray diffraction and transmission electron microscopy). The results should provide a fundamental understanding of the martensite transformation that occurs in TBC bond coats and thereby provide a science-based protocol for the development of long lasting, high performance TBC coatings. The technological motivation for this research is rooted in the fact that thermal barrier coatings offer tremendous opportunities for increasing the temperature capabilities and durability of components in aircraft engines and power turbines. In addition, the scientific challenges to be addressed, namely the development of combinatorial methods and novel micro-scale characterization techniques for assessing the stability, strength and performance of multilayered coatings, have a much broader application for the development of multicomponent structural materials. This Grant Opportunities for Academic Liaison with Industry (GOALI) collaboration includes closely meshed research activities and yearly personnel exchanges, and places Johns Hopkins students and faculty in direct contact with engineers and scientists at the GE Global Research Center. This broadens the education of the JHU students by providing invaluable technological and industrial experience. The benefits to GE include the availability of unique JHU experimental expertise and the ability to focus on fundamental research in an area that is of high technological interest.