Crack Arrest in Brittle Ceramics Subjected to Thermal Shock and Ablation  

作　　者：王艳伟 于合龙 唐翊翔 冯雪 

机构地区：[1]AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 [2]Center for Mechanics and Materials, Tsinghua University, Beijing 100084 [3]College of Information Technology, Jilin Agricultural University, Changchun 130118

出　　处：《Chinese Physics Letters》2014年第9期95-98,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 11227801, 11222220, 91116006, 10902059, 11372155 and 1320101001, and the Tsinghua University Initiative Scientific Research Program under Grant No 2011Z02173.

摘　　要：Ceramics are suitable for high temperature applications, especially for aerospace materials. When serving in high temperature environments, ceramics usually have to deal with the challenge of both thermal shock and ablation. We report the crack arrest in brittle ceramics during thermal shock and ablation. In our experiment, the specimens of Al2O3 are subjected to oxygen-propane flame heating until the temperature arises up to 1046℃ and then are cooled down in air. The crack occurs, however, it does not propagate when arrested by the microstructures （e.g., micro-bridges） of the crack tip. Such micro-bridge enhances the toughness of the brittle ceramics and prevents the crack propagation, which provides a hint for design of materials against the thermal shock.Ceramics are suitable for high temperature applications, especially for aerospace materials. When serving in high temperature environments, ceramics usually have to deal with the challenge of both thermal shock and ablation. We report the crack arrest in brittle ceramics during thermal shock and ablation. In our experiment, the specimens of Al2O3 are subjected to oxygen-propane flame heating until the temperature arises up to 1046℃ and then are cooled down in air. The crack occurs, however, it does not propagate when arrested by the microstructures （e.g., micro-bridges） of the crack tip. Such micro-bridge enhances the toughness of the brittle ceramics and prevents the crack propagation, which provides a hint for design of materials against the thermal shock.

分 类 号：TQ174.1[化学工程—陶瓷工业] X928.7[化学工程—硅酸盐工业]