Fracture Mechanism and Strength Evaluation of Functionally Graded Materials Taking Account of Inhomogeneity and Gradation of Microstructure

考虑微观结构不均匀性和梯度的功能梯度材料的断裂机制和强度评估

• 批准号: 15360050
• 负责人: TOHGO Keiichiro
• 金额: $ 9.41万
• 依托单位: Shizuoka 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-15360050/
• 关键词: Functionally graded materials; Composite materials; Inhomogeneity; Composite model; Strength evaluation; Fracture toughness test; Fracture test; Fatigue test; 破壊靭性試験

In order to apply ceramic-metal functionally graded materials (FGMs) as heat resistive structural materials, it is important to establish evaluation method of strength taking account of inhomogeneity and gradation of microstructure in FGMs and to make clear their fracture mechanism and strength under mechanical and thermal loading. In this investigation, numerical method for FGMs and test method for small specimens at room temperature to elevated temperature were established, and fracture behavior and strength of ceramic-metal FGMs were examined. Obtained results are summarized as follows.1.A model of two-phase composites is developed based on the micromechanics and concept of matricity for interpenetrating microstructure. By incorporating this model into a finite element method, the numerical method taking account of inhomogeneity and gradation of microstructure in FGMs is established.2.The size of FGMs fabricated by powder metallurgy is about 30mm in diameter and 10mm in thickness. The tests method to evaluate fracture mechanism, fracture toughness and crack growth behavior by small specimens under at room temperature to elevated temperature is established.3.Non-graded composites with deferent composition and FGMs are fabricated by powder metallurgy using partially stabilized zirconia (PSZ) and austenitic stainless steel (SUS 304). Elastic moduli, fracture strength, fracture toughness and crack growth behavior are examined for these materials at room temperature to elevated temperature and influence of inhomogeneity and gradation of microstructure is made clear.From the above results, method to predict the fracture behavior in FGMs and method to evaluate strength of FGMs are suggested based on the micromechanics and fracture mechanics.

为了将陶瓷-金属功能梯度材料应用于耐热结构材料，建立考虑其微观结构不均匀性和梯度的强度评价方法，明确其在机械和热载荷作用下的断裂机理和强度。在本研究中，建立了fgm的数值方法和室温至高温小试件的试验方法，并对陶瓷-金属fgm的断裂行为和强度进行了研究。所得结果总结如下：1。基于细观力学和互穿微观组织的基体概念，建立了两相复合材料的微观模型。将该模型与有限元方法相结合，建立了考虑fgm微结构不均匀性和梯度的数值方法。粉末冶金制备的fgm直径约为30mm，厚度约为10mm。建立了小试件在室温至高温条件下的断裂机理、断裂韧性和裂纹扩展行为的试验方法。采用部分稳定氧化锆（PSZ）和奥氏体不锈钢（sus304），采用粉末冶金技术制备了具有不同成分和fgm的非梯度复合材料。研究了这些材料在室温和高温下的弹性模量、断裂强度、断裂韧性和裂纹扩展行为，明确了微观组织的不均匀性和梯度的影响。在此基础上，提出了基于细观力学和断裂力学的FGMs断裂行为预测方法和强度评价方法。

项目成果

セラミックス-金属系傾斜機能材料の三点曲げ負荷による破壊過程

陶瓷金属功能梯度材料三点弯曲载荷断裂过程

• 发表时间: 2005
• 期刊: 日本機械学会論文集 A編 71巻・701号
• 作者: Keiichiro Tohgo;Keiichiro Tohgo;東郷 敬一郎;Keiichiro Tohgo;東郷敬一郎
• 通讯作者: 東郷敬一郎

Keiichiro Tohgo: "Two-Phase Composite Model Taking Account of Matricity of Microstructure and Its Application to Functionally Graded Materials"11th US-Japan Conference on Composite Materials. (2004)

Keiichiro Tohgo：“考虑微观结构矩阵的两相复合模型及其在功能梯度材料中的应用”第 11 届美日复合材料会议。

Keiichiro Tohgo: "Influence of Material Composition on Mechanical Properties and Fracture Behavior of Ceramic-Metal Composites"Asian Pacific Conference for Fracture and Strength '04. (2004)

Keiichiro Tohgo：“材料成分对陶瓷-金属复合材料机械性能和断裂行为的影响”亚太断裂与强度会议04。

Evaluation of Fracture Toughness Distribution in Ceramic-Metal Functionally Graded Materials

• DOI: 10.4028/www.scientific.net/kem.345-346.497
• 发表时间: 2007-08
• 期刊: Key Engineering Materials
• 作者: K. Tohgo;H. Araki;Y. Shimamura

複合材料のマイクロメカニクス・損傷解析の最新動向-IV 直交積層板の層内割れ損傷理論

复合材料微观力学和损伤分析最新趋势——IV正交层合板层内裂纹损伤理论

• 发表时间: 2005
• 期刊: 日本複合材料学会誌 31巻・5号
• 作者: Keiichiro Tohgo;Keiichiro Tohgo;東郷 敬一郎;Keiichiro Tohgo;東郷敬一郎;Keiichiro Tohgo;Keiichiro Tohgo;Keiichiro Tohgo;東郷敬一郎;東郷 敬一郎
• 通讯作者: 東郷 敬一郎