Thermomechanical Fracture of Compositionally Graded Thermal Barrier Coatings with Time-Dependent Behavior

具有时间依赖性行为的成分梯度热障涂层的热机械断裂

• 批准号: 0201287
• 负责人: Klod Kokini
• 金额: $ 25.38万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0201287&HistoricalAwards=false
• 关键词: Thermomechanical; Fracture; Compositionally; Graded; Thermal

ABSTRACTThermal barrier coatings (TBCs) offer the potential of increased performance for high temperature applications such as diesel engines, gas turbines and aircraft engines. Compositionally graded TBCs offer an excellent alternative to enhance the resistance to thermomechanical damage by providing a gradual transition in properties through the coating thickness. The objective of this project is to study analytically and experimentally, compositionally graded material systems of similar thermal resistances, but different architectures. At high temperatures, thermally activated time-dependent (viscoplastic) effects in the lower layers comprised of ceramic/bond coat alloy mixtures are expected to become significant. Therefore it is proposed to: (1) develop new models that allow the prediction of viscoplastic behavior of zirconia-bond coat alloy mixtures; (2) to use these models to study the time-dependent behavior, crack initiation and propagation in compositionally graded TBC systems of similar thermal resistances; (3) to perform controlled experiments with high heat fluxes that provide verification of the analytical predictions. The results are expected to yield design guidelines that would allow TBC designers to optimize the architecture of graded TBC systems to achieve improved durability for specific temperature loading conditions. In addition, these investigations will enhance basic scientific knowledge in the areas of viscoplastic deformation and fracture in two-phase and compositionally graded material systems. This new knowledge will be incorporated in undergraduate and graduate courses and help in the education of women and minority undergraduate students with the possibility they may embark on graduate studies.

热障涂层（TBCs）为柴油机、燃气轮机和航空发动机等高温应用提供了提高性能的潜力。成分梯度热障涂层提供了一个很好的选择，以提高抵抗热机械损伤，通过提供一个渐进的过渡性质通过涂层厚度。这个项目的目的是研究分析和实验，成分梯度材料系统的类似热阻，但不同的架构。在高温下，由陶瓷/粘结涂层合金混合物组成的下层中的热激活时间依赖性（粘塑性）效应预计将变得显著。因此，建议：（1）开发新的模型，可以预测氧化锆粘结层合金混合物的粘塑性行为;（2）使用这些模型来研究具有类似热阻的成分梯度TBC系统中的时间依赖性行为、裂纹萌生和扩展;（3）进行具有高热通量的受控实验，以验证分析预测。预计结果将产生设计指导方针，使TBC设计人员能够优化分级TBC系统的架构，以实现特定温度载荷条件下的耐久性提高。此外，这些调查将加强在两相和成分梯度材料系统的粘塑性变形和断裂领域的基础科学知识。这些新知识将被纳入本科和研究生课程，并有助于妇女和少数民族本科生的教育，使她们有可能开始研究生学习。