CAREER: Fundamental Micromechanics and Materials Dynamics of Thermal Barrier Coating Systems Containing Multiple Layers

9984899 weaver本研究的重点是了解控制热障涂层（TBC）中微组分机械性能的基本概念，即热暴露时间和温度的函数。该计划的具体目标是：(1)使用四种模型TBC系统，表征TBC系统的宏观和微观成分的特性作为热暴露的函数；(2)监测和分析TBC组分在热循环和等温氧化耦合机械应变过程中的位移；(3)基于降解机制和过程的微观结构和力学评估，开发TBC耐久性的物理和有限元模型。该教育计划的具体目标是：(1)加强本科课程，为学生提供研究商业上可行的厚膜和涂层材料的“实践”培训；(2)鼓励亚利桑那大学、斯蒂尔曼大学和FAMU的本科生攻读冶金与材料工程专业的研究生；(3)通过吸引未被充分代表的少数民族学生到阿拉巴马大学攻读本科和研究生课程来增加多样性。研究结果应该提供对TBC失效机制的基本理解，并导致更准确的寿命预测模型的发展。热障涂层（TBC）已经使用了近三十年，以延长在恶劣环境下运行的飞机涡轮的性能。目前的TBC通常是多层系统，在金属结合涂层上应用绝缘陶瓷面漆；后者直接沉积在组件的表面上。虽然TBC具有理想的绝缘性能，但耐久性和可靠性问题限制了它们的应用。由于缺乏有关微观结构退化对TBC力学响应影响的基础数据，阻碍了准确寿命预测模型的发展。＊＊＊

9984899WeaverThis research focuses on understanding the fundamental concepts controlling the mechanical properties of microconstituents in thermal barrier coatings (TBC) as a function of thermal exposure, both time and temperature. The specific goals of the proposed program are: (1) Characterize the properties of the macro- and micro-constituents of the TBC system as a function of thermal exposure using four model TBC systems; (2) Monitor and analyze the displacements of the TBC constituents during thermal cycling and isothermal oxidation coupled with mechanical strain; and (3) Develop physical and finite element models of TBC durability based on microstructural and mechanical evaluations of degradation mechanisms and processes. The specific objectives of the educational plan are: (1) Enhance the undergraduate curriculum by providing students with "hands on" training in the study of commercially viable thick films and coating materials; (2) Encourage undergraduate students from UA, Stillman, and FAMU to pursue graduate studies in Metallurgical and Materials Engineering; and (3) Increase diversity by attracting underrepresented minority students to undergraduate and graduate study at The University of Alabama. %%%The research results should provide fundamental understanding of the mechanisms contributing towards TBC failure and lead to the development of more accurate life prediction models. Thermal barrier coatings (TBC's) have been used for nearly three decades to extend the performance of aircraft turbines operating in hostile environments. Current TBC's are typically multilayer systems incorporating an insulating ceramic topcoat applied over a metallic bond coat; the latter is deposited directly on the surface of the component. While TBC's exhibit the desired insulating capability, it is the durability and reliability issues that have limited their application. A lack of fundamental data concerning the influence of microstructural degradation on the mechanical response of TBC's has impeded the development of accurate life prediction models. ***