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Evaluation of Reliability in Harmonic Material System

谐波材料系统的可靠性评估

基本信息

批准号：
11221205
负责人：
ENOKI Manabu
金额：
$ 34.69万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

High performance is recently requested for materials, and also smart materials system which combine materials and structure has been developed. Novel approach for materials design which is different from the conventional one is expected. In these materials a new method to ensure a reliability of materials or a design of materials and structure for easy screening becomes important problems. In this research a novel non-contact nondestructive evaluation method was investigated based on the new approach of materials harmonic design, and also layered materials consist of metal and intermetallic component was developed because these materials demonstrates excellent crack prorogation resistance. Thermal cycle tests of alumina/SUS304 steel coatings was employed and acoustic emission waveforms due to microfracture during tests was successfully detected by laser AE system. The development of laser interferometer with high sensitivity is requested for the detection and analysis of small microfracture. We developed the laser AE system for improvement of the sensitivity and reduced the noise components by newly developed demodulator. The noise of the system was also improve by the focused detection points and averaging signals. The system finally enabled the measurement of AE with high signal/noise ratio. Processing conditions for Ti/Ti-Al layered materials were investigated, and mechanical properties and crack propagation process were analyzed. Also Ni/Ni-Al layered materials with thin metal layer was investigated. Heat treatment of Ni layer was tried to improve the ductility of materials and crack propagation resistance. The mechanisms of fabrication of intermetallic phase and the effect of residual stress on fracture toughness were also studied and finally a guide for materials design was obtained.

近年来，人们对材料提出了高性能的要求，联合收割机将材料与结构相结合的智能材料系统也应运而生。期待着不同于传统的材料设计新方法的出现。在这些材料中，确保材料可靠性的新方法或易于筛选的材料和结构的设计成为重要问题。本研究基于材料调和设计的新方法，研究了一种新型的非接触无损评价方法，并开发了由金属和金属间化合物组成的层状材料，因为这些材料具有优异的抗裂纹扩展能力。对氧化铝/SUS 304钢涂层进行了热循环试验，利用激光声发射系统成功地检测到了试验过程中微裂纹产生的声发射波形。微小裂纹的检测和分析需要高灵敏度的激光干涉仪。我们开发了激光AE系统，以提高灵敏度，并通过新开发的解调器降低了噪声分量。通过对检测点的聚焦和信号的平均化，改善了系统的噪声。该系统最终实现了高信噪比的声发射测量。研究了Ti/Ti-Al层状复合材料的制备工艺，分析了复合材料的力学性能和裂纹扩展过程。并对Ni/Ni-Al层状材料进行了研究。对镍层进行热处理，以提高材料的塑性和抗裂纹扩展能力。研究了金属间化合物相的形成机理及残余应力对断裂韧性的影响，为材料设计提供了依据。