NSF-EC Activity: Dynamics of Layered, Multifunctional Surfaces

NSF-EC 活动：分层、多功能表面的动力学

• 批准号: 0099695
• 负责人: Carlos Levi
• 金额: $ 156.08万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0099695&HistoricalAwards=false
• 关键词: NSF; EC; Activity; Dynamics; Layered

Abstract: 0099695Univ. of Santa BarbaraCarlos G. LeviA multidisciplinary scientific team will undertake a collaborative program to investigate the dynamics of layered, multifunctional surfaces. The focus is on coating systems that provide both thermal insulation and oxidation/corrosion protection for thermostructural components. The overarching intellectual challenge is establishing a science-based protocol for optimizing functionality while integrating thermomechanically and thermochemically disparate materials that experience large temperature extremes. These systems are inherently metastable and evolve via morphological changes, diffusional interactions and thermomechanically-induced stresses that generally degrade performance and limit durability. The program aims to develop a fundamental understanding of the underlying mechanisms that could provide a basis for designing superior, durable surfaces. The scientific themes involve phase equilibria between oxides and intermetallics, diffusive and thermal transport phenomena in oxides, fundamental mechanisms of deformation and basic mechanistic aspects of oxide growth. Specific objectives seek to elucidate (a) the role of composition on the mechanisms of surface diffusion in fluorite-structured oxides, as well as boundary diffusion in intermetallics; (b) the thermomechanical behavior of individual layers, as they relate to chemistry and microstructure, and complexities associated with their interaction; (c) the interplay between processing and material parameters via microstructural modifications; and (d) the mechanisms governing thermal transport in porous multicomponent oxides. The materials systems of interest are ceramics based on zirconia and rare earth oxides, as well as Ni-based intermetallics alloyed with platinum group metals. The synthesis technologies are predominantly vapor-based, with precursor methods and melt processing used in generating model specimens. Thermodynamic, kinetic and mechanics modeling activities will be an essential complement of the experimental activities.The program offers a balanced set of educational, scientific and technological benefits. The technological motivation derives from the drive to expand the limits and durability of structural materials, wherein durable multifunctional surfaces represent a materials challenge of highest priority. These material systems are essential to the pursuit of improved efficiency and reduced environmental impact for gas turbines, a predominant source of power for global electrification, aircraft and marine transportation, as well as numerous industrial processes. The societal and economic benefits are thus self-evident but are presently limited because of insufficient scientific understanding to guide needed improvements in materials design, processing and performance. The complexity and richness in fundamental issues associated with the dynamics of these layers provide the scientific motivation as well as the need for an interdisciplinary research approach. The team assembled has an unprecedented combination of expertise and available facilities to undertake this research. They are all closely involved in working with students and motivated by the unique educational opportunity afforded by the NSF-EC program. Accordingly, the projects will be defined to foster collaboration among American and European students. Mechanisms will be provided for extended reciprocal visits of students working together on a given topic, to experience first hand how research is done at the partner institution. By working on a broad

摘要：0099695Univ。 Santa Barbaracarlos G. Levia多学科科学团队将进行协作计划，以调查分层多功能表面的动态。重点是为热体组件提供热绝缘和氧化/腐蚀保护的涂料系统。总体智力挑战是建立一种基于科学的协议，以优化功能，同时在热机械和热化学上不同的材料集成，这些材料经历了极端的温度。这些系统本质上是可稳定的，并且通过形态学变化，扩散相互作用和热机械诱导的应力演变，这些应力通常会降低性能并限制耐用性。该计划旨在建立对可以为设计出色，耐用表面设计基础的基本机制的基本理解。科学主题涉及氧化物与金属间的相之间的平衡，氧化物中的扩散和热传输现象，变形的基本机制以及氧化物生长的基本机械方面。特定的目标旨在阐明（a）组成对氟结构氧化物中表面扩散机制的作用，以及金属间的边界扩散； （b）与化学和微观结构有关的各个层的热机械行为以及与其相互作用相关的复杂性； （c）通过微观结构修改在处理和材料参数之间的相互作用； （d）管理多孔多组分氧化物中热传输的机制。感兴趣的材料系统是基于氧化锆和稀土氧化物的陶瓷，以及与铂类金属合金的基于Ni的金属间。合成技术主要是基于蒸气的，具有前体方法和用于生成模型样品的熔体处理。热力学，动力学和力学建模活动将是实验活动的重要补充。该计划提供了一组平衡的教育，科学和技术优势。技术动机源于扩大结构材料的限制和耐用性的动力，其中耐用的多功能表面代表了最高优先级的材料挑战。这些材料系统对于追求提高效率并减少对燃气轮机的环境影响是必不可少的，燃气轮机是全球电气化，飞机和海洋运输的主要动力以及众多工业过程。因此，社会和经济利益是不言而喻的，但由于不足的科学理解无法指导材料设计，加工和性能所需的改进，因此目前受到限制。与这些层的动态相关的基本问题的复杂性和丰富性提供了科学动机以及对跨学科研究方法的需求。团队组装的团队具有前所未有的专业知识和可用设施的组合，可以进行这项研究。他们都密切参与与学生合作，并受到NSF-EC计划提供的独特教育机会的激励。因此，这些项目将被定义为促进美国和欧洲学生之间的合作。将提供机制，用于在给定主题上共同努力的学生进行扩展的相互访问，以亲身体验合作伙伴机构的研究。通过广泛的工作