高温热冲击下陶瓷材料的动态裂纹扩展与失效机理

项目名称： 高温热冲击下陶瓷材料的动态裂纹扩展与失效机理

项目编号： No.11502127

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 夏彪

作者单位： 清华大学

项目金额： 20万元

中文摘要： 陶瓷因具有高熔点、耐腐蚀、耐磨损和高温稳定性等优点而成为航空航天领域最具前景的候选材料之一。但是陶瓷本征脆性，在高温极端环境下，易发生热冲击失效并导致结构发生突发的灾难性事故。本项目以航空航天工业中的耐高温陶瓷材料为研究对象，以动态裂纹扩展机理为研究着力点，通过发展高温环境下变形场、温度场的动态在线同步测量方法，探索极端环境下材料受到局部高速热冲击时的动态裂纹扩展规律和破坏形式。在此基础上，结合理论和数值计算方法，分析高温复杂环境下陶瓷材料的应力场、热力耦合机制及裂纹路径选择，从理论上构建温度与动态裂纹扩展几何形态的关系，提出不同温度条件下的整体失效判据，实现材料在极端环境下的抗热冲击性能的评估，为航空航天工业相关材料的设计和制造提供基础理论。

中文关键词： 抗热震性能；动态性能；高温环境；耐久性热冲击；超高温陶瓷

英文摘要： Ceramics are suitable for high temperature applications, especially for aerospace materials. However, compared to the high melting point, corrosion resistance, wear resistance and high-temperature stability, ceramics are intrinsic brittle and prone to experience thermal shock failure and can lead to sudden catastrophic accidents. This project mainly focuses on the high-temperature ceramics subjected to drastic temperature change in service conditions, and studies the dynamic crack propagation mechanism. By developing the in-situ synchronous dynamic measurement methods for both termperature field and deformation field, the dynamic crack propagating law and failure modes of ceramics are explored when subjected to partial high-speed thermal shock in extreme environments. On this basis, by combining the theoretical with numerical methods, we will analyze the stress field, thermal-structural coupling mechanism and the crack path selection to eatablish a relationship between temperature and dynamic crack patterns, and put forward the overall failure criterion at different temperatures. The evaluation of the thermal shock resistance provides the theoretical basis for the design and manufacture of aerospace-related materials.

英文关键词： Thermal shock resistance;Dynamic properties;High-temperature environment;Durability of thermal shock;Ultra-high temperature ceramic