Study on the Thermal Shock Fracture Mechanism of Ceramics Based on the Dynamic Characterization of Thermal Stress and Microfracture Process

基于热应力动态表征和微断裂过程的陶瓷热震断裂机理研究

• 批准号: 15360349
• 负责人: WAKAYAMA Shuichi
• 金额: $ 9.73万
• 依托单位: TOKYO METROPOLITAN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15360349/
• 关键词: Ceramics; Thermal Schock Fracture; AE Analysis; FEM; Microfracture Process; Long-Term Reliability; 結晶粒径; 多軸応力; ディスクオンロッド試験; 熱応力; き裂進展抵抗; 高靭化機構; ディスクンロッド試験; 主き裂形成理解応力; き裂進展経路; 最大周方向応力

Ceramic materials used at elevated temperatures are usually subjected to damage due to thermal shock fracture. One of the most popular thermal shock tests is the water quench test, in which the critical temperature difference, where samples are subjected to severe damage, is used as a measure of the thermal shock resistance. However the characterization of microfracture process under thermal shock as well as transient thermal stress field is indispensable, since thermal shock fracture is caused by the accumulation of microscopic damages such as microcrackings under thermal stress. In this project, a new experimental technique for the investigation of thermal shock fracture behavior, Disc-on-Rod test, is proposed. The temperature fields in the specimen were measured and used to calculate the 2 dimensional thermal stress field. Furthermore, microfracture process was characterized by AE measurement. In the present project, followings have been achieved.1. Experimental system of Disc-on-Rod test was significantly developed. The in-situ observation of crack initiation and propagation behavior under thermal shock was enabled by digital video camera unit. Furthermore, the 3D-analysis of thermal stress was enabled by introducing full-version FEM code (ANSYS).2. The crack propagation behavior under thermal shock was characterized dynamically. The dependence of crack stability on the length of pre-crack was understood quantitatively, which showed good agreement of theoretical prediction by Hasselman's unified theory. In addition, the crack growth behavior of toughened ceramic composites was characterized successfully.3. Non-destructive evaluation technique of microfracture process in ceramics under mechanical loading was drastically developed and applied to bioceramics. The assessment technique of long-term reliability of ceramics was developed and will be applied to thermal shock fracture.

高温下使用的陶瓷材料通常由于热休克骨折而损坏。最受欢迎的热冲击测试之一是水淬火测试，其中样品受到严重损坏的临界温度差，被用作衡量热冲击电阻的量度。然而，在热休克和瞬态热应力场下的微裂缝过程的表征是必不可少的，因为热休克断裂是由于微观损害（例如在热应力下的微裂纹）的积累引起的。在该项目中，提出了一种用于调查热休克裂缝行为的新实验技术，即圆盘杆子测试。测量样品中的温度场并用于计算2维热应力场。此外，通过AE测量表征了微裂纹过程。在本项目中，已经实现了以下项目。1。圆盘旋转测试的实验系统得到了显着发展。数码摄像机单元实现了对热冲击下裂纹启动和传播行为的原位观察。此外，通过引入全面的FEM代码（ANSYS）.2实现了热应力的3D分析。在热冲击下的裂纹传播行为是动态表征的。裂纹稳定性对裂缝长度的依赖性被定量地理解，这表明了Hasselman的统一理论对理论预测的良好一致。另外，成功表征了加强的陶瓷复合材料的裂纹生长行为3。机械负载下的陶瓷中微裂缝过程的非破坏性评估技术已大大开发并应用于生物陶瓷。开发了陶瓷长期可靠性的评估技术，并将应用于热休克骨折。

项目成果

Acoustic Emission from Micro-Fracture Processes of Bio-Ceramics in Simulated Body Environment

模拟人体环境中生物陶瓷微断裂过程的声发射

• 发表时间: 2003
• 期刊: Journal of Acoustic Emission Vol.21
• 作者: Shuichi WAKAYAMA;Teppei KAWAKAMI;Satoshi KOBAYASHI;Mamoru AIZAWA;Akira NOZUE
• 通讯作者: Akira NOZUE

Experimental Approach to Microfracture Process of Ceramics under Thermal Shock

陶瓷热冲击微断裂过程的实验方法

• 发表时间: 2005
• 期刊: Fracture Mechanics of Ceramics
• 作者: Shuichi WAKAYAMA;Kousuke NISHINO;Kouhei KUBOTA;Toshiya WADA;Satoshi KOBAYASHI
• 通讯作者: Satoshi KOBAYASHI

Long-Term Reliability Assessment of Bioceramics for Artificial Joints using Microdamage Monitoring by AE

使用 AE 微损伤监测对人工关节生物陶瓷进行长期可靠性评估

• 发表时间: 2006
• 期刊: Key Engineering Materials Vols.309-311
• 作者: Shuichi WAKAYAMA;Teppei KAWAKAMI;Junji IKEDA
• 通讯作者: Junji IKEDA

AE Morinotoring of Microdamages in Bioceramics for Artificial Joints under Simulated Body Environment

模拟人体环境下人工关节生物陶瓷微损伤的声发射监测

• 发表时间: 2006
• 期刊: JSME International Journal Vol.49,No.1
• 作者: Shuichi WAKAYAMA;Yasuhiro SUZUKI;Toyokatsu OSHIMA;Satoshi KOBAYASHI
• 通讯作者: Satoshi KOBAYASHI

AE characterization of fracture behavior in bioceramics under simulated body environment

• DOI: 10.1299/jsmea.46.348
• 发表时间: 2003-07
• 期刊: Jsme International Journal Series A-solid Mechanics and Material Engineering
• 作者: Teppei Kawakami;Satoshi Kobayashi;S. Wakayama